xref: /dragonfly/sys/dev/netif/sn/if_sn.c (revision c3762235)
1 /*
2  * Copyright (c) 1996 Gardner Buchanan <gbuchanan@shl.com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *      This product includes software developed by Gardner Buchanan.
16  * 4. The name of Gardner Buchanan may not be used to endorse or promote
17  *    products derived from this software without specific prior written
18  *    permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  *
31  *   $FreeBSD: src/sys/dev/sn/if_sn.c,v 1.7.2.3 2001/02/04 04:38:38 toshi Exp $
32  */
33 
34 /*
35  * This is a driver for SMC's 9000 series of Ethernet adapters.
36  *
37  * This FreeBSD driver is derived from the smc9194 Linux driver by
38  * Erik Stahlman and is Copyright (C) 1996 by Erik Stahlman.
39  * This driver also shamelessly borrows from the FreeBSD ep driver
40  * which is Copyright (C) 1994 Herb Peyerl <hpeyerl@novatel.ca>
41  * All rights reserved.
42  *
43  * It is set up for my SMC91C92 equipped Ampro LittleBoard embedded
44  * PC.  It is adapted from Erik Stahlman's Linux driver which worked
45  * with his EFA Info*Express SVC VLB adaptor.  According to SMC's databook,
46  * it will work for the entire SMC 9xxx series. (Ha Ha)
47  *
48  * "Features" of the SMC chip:
49  *   4608 byte packet memory. (for the 91C92.  Others have more)
50  *   EEPROM for configuration
51  *   AUI/TP selection
52  *
53  * Authors:
54  *      Erik Stahlman                   erik@vt.edu
55  *      Herb Peyerl                     hpeyerl@novatel.ca
56  *      Andres Vega Garcia              avega@sophia.inria.fr
57  *      Serge Babkin                    babkin@hq.icb.chel.su
58  *      Gardner Buchanan                gbuchanan@shl.com
59  *
60  * Sources:
61  *    o   SMC databook
62  *    o   "smc9194.c:v0.10(FIXED) 02/15/96 by Erik Stahlman (erik@vt.edu)"
63  *    o   "if_ep.c,v 1.19 1995/01/24 20:53:45 davidg Exp"
64  *
65  * Known Bugs:
66  *    o   The hardware multicast filter isn't used yet.
67  *    o   Setting of the hardware address isn't supported.
68  *    o   Hardware padding isn't used.
69  */
70 
71 /*
72  * Modifications for Megahertz X-Jack Ethernet Card (XJ-10BT)
73  *
74  * Copyright (c) 1996 by Tatsumi Hosokawa <hosokawa@jp.FreeBSD.org>
75  *                       BSD-nomads, Tokyo, Japan.
76  */
77 /*
78  * Multicast support by Kei TANAKA <kei@pal.xerox.com>
79  * Special thanks to itojun@itojun.org
80  */
81 
82 #undef	SN_DEBUG	/* (by hosokawa) */
83 
84 #include <sys/param.h>
85 #include <sys/systm.h>
86 #include <sys/kernel.h>
87 #include <sys/interrupt.h>
88 #include <sys/errno.h>
89 #include <sys/sockio.h>
90 #include <sys/malloc.h>
91 #include <sys/mbuf.h>
92 #include <sys/socket.h>
93 #include <sys/syslog.h>
94 #include <sys/serialize.h>
95 #include <sys/module.h>
96 #include <sys/bus.h>
97 #include <sys/rman.h>
98 #include <sys/thread2.h>
99 
100 #include <net/ethernet.h>
101 #include <net/if.h>
102 #include <net/ifq_var.h>
103 #include <net/if_arp.h>
104 #include <net/if_dl.h>
105 #include <net/if_types.h>
106 #include <net/if_mib.h>
107 
108 #ifdef INET
109 #include <netinet/in.h>
110 #include <netinet/in_systm.h>
111 #include <netinet/in_var.h>
112 #include <netinet/ip.h>
113 #endif
114 
115 #include <net/bpf.h>
116 #include <net/bpfdesc.h>
117 
118 #include <machine/clock.h>
119 
120 #include "if_snreg.h"
121 #include "if_snvar.h"
122 
123 /* Exported variables */
124 devclass_t sn_devclass;
125 
126 static int snioctl(struct ifnet * ifp, u_long, caddr_t, struct ucred *);
127 
128 static void snresume(struct ifnet *);
129 
130 void sninit(void *);
131 void snread(struct ifnet *);
132 void snreset(struct sn_softc *);
133 void snstart(struct ifnet *, struct ifaltq_subque *);
134 void snstop(struct sn_softc *);
135 void snwatchdog(struct ifnet *);
136 
137 static void sn_setmcast(struct sn_softc *);
138 static int sn_getmcf(struct arpcom *ac, u_char *mcf);
139 static u_int smc_crc(u_char *);
140 
141 DECLARE_DUMMY_MODULE(if_sn);
142 
143 /* I (GB) have been unlucky getting the hardware padding
144  * to work properly.
145  */
146 #define SW_PAD
147 
148 static const char *chip_ids[15] = {
149 	NULL, NULL, NULL,
150 	 /* 3 */ "SMC91C90/91C92",
151 	 /* 4 */ "SMC91C94",
152 	 /* 5 */ "SMC91C95",
153 	NULL,
154 	 /* 7 */ "SMC91C100",
155 	 /* 8 */ "SMC91C100FD",
156 	NULL, NULL, NULL,
157 	NULL, NULL, NULL
158 };
159 
160 int
161 sn_attach(device_t dev)
162 {
163 	struct sn_softc *sc = device_get_softc(dev);
164 	struct ifnet   *ifp = &sc->arpcom.ac_if;
165 	u_short         i;
166 	u_char         *p;
167 	int             rev;
168 	u_short         address;
169 	int		j;
170 	int		error;
171 
172 	sn_activate(dev);
173 
174 	snstop(sc);
175 
176 	sc->dev = dev;
177 	sc->pages_wanted = -1;
178 
179 	device_printf(dev, " ");
180 
181 	SMC_SELECT_BANK(3);
182 	rev = inw(BASE + REVISION_REG_W);
183 	if (chip_ids[(rev >> 4) & 0xF])
184 		kprintf("%s ", chip_ids[(rev >> 4) & 0xF]);
185 
186 	SMC_SELECT_BANK(1);
187 	i = inw(BASE + CONFIG_REG_W);
188 	kprintf("%s\n", i & CR_AUI_SELECT ? "AUI" : "UTP");
189 
190 	if (sc->pccard_enaddr)
191 		for (j = 0; j < 3; j++) {
192 			u_short	w;
193 
194 			w = (u_short)sc->arpcom.ac_enaddr[j * 2] |
195 				(((u_short)sc->arpcom.ac_enaddr[j * 2 + 1]) << 8);
196 			outw(BASE + IAR_ADDR0_REG_W + j * 2, w);
197 		}
198 
199 	/*
200 	 * Read the station address from the chip. The MAC address is bank 1,
201 	 * regs 4 - 9
202 	 */
203 	SMC_SELECT_BANK(1);
204 	p = (u_char *) & sc->arpcom.ac_enaddr;
205 	for (i = 0; i < 6; i += 2) {
206 		address = inw(BASE + IAR_ADDR0_REG_W + i);
207 		p[i + 1] = address >> 8;
208 		p[i] = address & 0xFF;
209 	}
210 	ifp->if_softc = sc;
211 	if_initname(ifp, "sn", device_get_unit(dev));
212 	ifp->if_mtu = ETHERMTU;
213 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
214 	ifp->if_start = snstart;
215 	ifp->if_ioctl = snioctl;
216 	ifp->if_watchdog = snwatchdog;
217 	ifp->if_init = sninit;
218 	ifq_set_maxlen(&ifp->if_snd, IFQ_MAXLEN);
219 	ifq_set_ready(&ifp->if_snd);
220 	ifp->if_timer = 0;
221 
222 	ether_ifattach(ifp, sc->arpcom.ac_enaddr, NULL);
223 
224 	ifq_set_cpuid(&ifp->if_snd, rman_get_cpuid(sc->irq_res));
225 
226 	error = bus_setup_intr(dev, sc->irq_res, INTR_MPSAFE,
227 			       sn_intr, sc, &sc->intrhand,
228 			       ifp->if_serializer);
229 	if (error) {
230 		ether_ifdetach(ifp);
231 		sn_deactivate(dev);
232 		return error;
233 	}
234 
235 	return 0;
236 }
237 
238 
239 /*
240  * Reset and initialize the chip
241  */
242 void
243 sninit(void *xsc)
244 {
245 	struct sn_softc *sc = xsc;
246 	struct ifnet *ifp = &sc->arpcom.ac_if;
247 	int             flags;
248 	int             mask;
249 
250 	/*
251 	 * This resets the registers mostly to defaults, but doesn't affect
252 	 * EEPROM.  After the reset cycle, we pause briefly for the chip to
253 	 * be happy.
254 	 */
255 	SMC_SELECT_BANK(0);
256 	outw(BASE + RECV_CONTROL_REG_W, RCR_SOFTRESET);
257 	SMC_DELAY();
258 	outw(BASE + RECV_CONTROL_REG_W, 0x0000);
259 	SMC_DELAY();
260 	SMC_DELAY();
261 
262 	outw(BASE + TXMIT_CONTROL_REG_W, 0x0000);
263 
264 	/*
265 	 * Set the control register to automatically release succesfully
266 	 * transmitted packets (making the best use out of our limited
267 	 * memory) and to enable the EPH interrupt on certain TX errors.
268 	 */
269 	SMC_SELECT_BANK(1);
270 	outw(BASE + CONTROL_REG_W, (CTR_AUTO_RELEASE | CTR_TE_ENABLE |
271 				    CTR_CR_ENABLE | CTR_LE_ENABLE));
272 
273 	/* Set squelch level to 240mV (default 480mV) */
274 	flags = inw(BASE + CONFIG_REG_W);
275 	flags |= CR_SET_SQLCH;
276 	outw(BASE + CONFIG_REG_W, flags);
277 
278 	/*
279 	 * Reset the MMU and wait for it to be un-busy.
280 	 */
281 	SMC_SELECT_BANK(2);
282 	outw(BASE + MMU_CMD_REG_W, MMUCR_RESET);
283 	while (inw(BASE + MMU_CMD_REG_W) & MMUCR_BUSY)	/* NOTHING */
284 		;
285 
286 	/*
287 	 * Disable all interrupts
288 	 */
289 	outb(BASE + INTR_MASK_REG_B, 0x00);
290 
291 	sn_setmcast(sc);
292 
293 	/*
294 	 * Set the transmitter control.  We want it enabled.
295 	 */
296 	flags = TCR_ENABLE;
297 
298 #ifndef SW_PAD
299 	/*
300 	 * I (GB) have been unlucky getting this to work.
301 	 */
302 	flags |= TCR_PAD_ENABLE;
303 #endif	/* SW_PAD */
304 
305 	outw(BASE + TXMIT_CONTROL_REG_W, flags);
306 
307 
308 	/*
309 	 * Now, enable interrupts
310 	 */
311 	SMC_SELECT_BANK(2);
312 
313 	mask = IM_EPH_INT |
314 		IM_RX_OVRN_INT |
315 		IM_RCV_INT |
316 		IM_TX_INT;
317 
318 	outb(BASE + INTR_MASK_REG_B, mask);
319 	sc->intr_mask = mask;
320 	sc->pages_wanted = -1;
321 
322 
323 	/*
324 	 * Mark the interface running but not active.
325 	 */
326 	ifp->if_flags |= IFF_RUNNING;
327 	ifq_clr_oactive(&ifp->if_snd);
328 
329 	/*
330 	 * Attempt to push out any waiting packets.
331 	 */
332 	if_devstart(ifp);
333 }
334 
335 
336 void
337 snstart(struct ifnet *ifp, struct ifaltq_subque *ifsq)
338 {
339 	struct sn_softc *sc = ifp->if_softc;
340 	u_int  len;
341 	struct mbuf *m;
342 	struct mbuf    *top;
343 	int             pad;
344 	int             mask;
345 	u_short         length;
346 	u_short         numPages;
347 	u_char          packet_no;
348 	int             time_out;
349 
350 	ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);
351 
352 	if ((ifp->if_flags & IFF_RUNNING) == 0 || ifq_is_oactive(&ifp->if_snd))
353 		return;
354 
355 	if (sc->pages_wanted != -1) {
356 		/* XXX should never happen */
357 		kprintf("%s: snstart() while memory allocation pending\n",
358 		       ifp->if_xname);
359 		ifq_set_oactive(&ifp->if_snd);
360 		return;
361 	}
362 startagain:
363 
364 	/*
365 	 * Sneak a peek at the next packet
366 	 */
367 	m = ifq_dequeue(&ifp->if_snd);
368 	if (m == NULL)
369 		return;
370 
371 	/*
372 	 * Compute the frame length and set pad to give an overall even
373 	 * number of bytes.  Below we assume that the packet length is even.
374 	 */
375 	for (len = 0, top = m; m; m = m->m_next)
376 		len += m->m_len;
377 
378 	pad = (len & 1);
379 
380 	/*
381 	 * We drop packets that are too large. Perhaps we should truncate
382 	 * them instead?
383 	 */
384 	if (len + pad > ETHER_MAX_LEN - ETHER_CRC_LEN) {
385 		kprintf("%s: large packet discarded (A)\n", ifp->if_xname);
386 		IFNET_STAT_INC(&sc->arpcom.ac_if, oerrors, 1);
387 		m_freem(top);
388 		goto readcheck;
389 	}
390 #ifdef SW_PAD
391 
392 	/*
393 	 * If HW padding is not turned on, then pad to ETHER_MIN_LEN.
394 	 */
395 	if (len < ETHER_MIN_LEN - ETHER_CRC_LEN)
396 		pad = ETHER_MIN_LEN - ETHER_CRC_LEN - len;
397 
398 #endif	/* SW_PAD */
399 
400 	length = pad + len;
401 
402 	/*
403 	 * The MMU wants the number of pages to be the number of 256 byte
404 	 * 'pages', minus 1 (A packet can't ever have 0 pages. We also
405 	 * include space for the status word, byte count and control bytes in
406 	 * the allocation request.
407 	 */
408 	numPages = (length + 6) >> 8;
409 
410 
411 	/*
412 	 * Now, try to allocate the memory
413 	 */
414 	SMC_SELECT_BANK(2);
415 	outw(BASE + MMU_CMD_REG_W, MMUCR_ALLOC | numPages);
416 
417 	/*
418 	 * Wait a short amount of time to see if the allocation request
419 	 * completes.  Otherwise, I enable the interrupt and wait for
420 	 * completion asyncronously.
421 	 */
422 
423 	time_out = MEMORY_WAIT_TIME;
424 	do {
425 		if (inb(BASE + INTR_STAT_REG_B) & IM_ALLOC_INT)
426 			break;
427 	} while (--time_out);
428 
429 	if (!time_out) {
430 
431 		/*
432 		 * No memory now.  Oh well, wait until the chip finds memory
433 		 * later.   Remember how many pages we were asking for and
434 		 * enable the allocation completion interrupt. Also set a
435 		 * watchdog in case  we miss the interrupt. We mark the
436 		 * interface active since there is no point in attempting an
437 		 * snstart() until after the memory is available.
438 		 */
439 		mask = inb(BASE + INTR_MASK_REG_B) | IM_ALLOC_INT;
440 		outb(BASE + INTR_MASK_REG_B, mask);
441 		sc->intr_mask = mask;
442 
443 		ifp->if_timer = 1;
444 		ifq_set_oactive(&ifp->if_snd);
445 		sc->pages_wanted = numPages;
446 		ifq_prepend(&ifp->if_snd, top);
447 
448 		return;
449 	}
450 	/*
451 	 * The memory allocation completed.  Check the results.
452 	 */
453 	packet_no = inb(BASE + ALLOC_RESULT_REG_B);
454 	if (packet_no & ARR_FAILED) {
455 		kprintf("%s: Memory allocation failed\n", ifp->if_xname);
456 		ifq_prepend(&ifp->if_snd, top);
457 		goto startagain;
458 	}
459 	/*
460 	 * We have a packet number, so tell the card to use it.
461 	 */
462 	outb(BASE + PACKET_NUM_REG_B, packet_no);
463 
464 	/*
465 	 * Point to the beginning of the packet
466 	 */
467 	outw(BASE + POINTER_REG_W, PTR_AUTOINC | 0x0000);
468 
469 	/*
470 	 * Send the packet length (+6 for status, length and control byte)
471 	 * and the status word (set to zeros)
472 	 */
473 	outw(BASE + DATA_REG_W, 0);
474 	outb(BASE + DATA_REG_B, (length + 6) & 0xFF);
475 	outb(BASE + DATA_REG_B, (length + 6) >> 8);
476 
477 	/*
478 	 * Push out the data to the card.
479 	 */
480 	for (m = top; m != NULL; m = m->m_next) {
481 
482 		/*
483 		 * Push out words.
484 		 */
485 		outsw(BASE + DATA_REG_W, mtod(m, caddr_t), m->m_len / 2);
486 
487 		/*
488 		 * Push out remaining byte.
489 		 */
490 		if (m->m_len & 1)
491 			outb(BASE + DATA_REG_B, *(mtod(m, caddr_t) + m->m_len - 1));
492 	}
493 
494 	/*
495 	 * Push out padding.
496 	 */
497 	while (pad > 1) {
498 		outw(BASE + DATA_REG_W, 0);
499 		pad -= 2;
500 	}
501 	if (pad)
502 		outb(BASE + DATA_REG_B, 0);
503 
504 	/*
505 	 * Push out control byte and unused packet byte The control byte is 0
506 	 * meaning the packet is even lengthed and no special CRC handling is
507 	 * desired.
508 	 */
509 	outw(BASE + DATA_REG_W, 0);
510 
511 	/*
512 	 * Enable the interrupts and let the chipset deal with it Also set a
513 	 * watchdog in case we miss the interrupt.
514 	 */
515 	mask = inb(BASE + INTR_MASK_REG_B) | (IM_TX_INT | IM_TX_EMPTY_INT);
516 	outb(BASE + INTR_MASK_REG_B, mask);
517 	sc->intr_mask = mask;
518 
519 	outw(BASE + MMU_CMD_REG_W, MMUCR_ENQUEUE);
520 
521 	ifq_set_oactive(&ifp->if_snd);
522 	ifp->if_timer = 1;
523 
524 	BPF_MTAP(ifp, top);
525 
526 	IFNET_STAT_INC(ifp, opackets, 1);
527 	m_freem(top);
528 
529 readcheck:
530 
531 	/*
532 	 * Is another packet coming in?  We don't want to overflow the tiny
533 	 * RX FIFO.  If nothing has arrived then attempt to queue another
534 	 * transmit packet.
535 	 */
536 	if (inw(BASE + FIFO_PORTS_REG_W) & FIFO_REMPTY)
537 		goto startagain;
538 }
539 
540 
541 
542 /* Resume a packet transmit operation after a memory allocation
543  * has completed.
544  *
545  * This is basically a hacked up copy of snstart() which handles
546  * a completed memory allocation the same way snstart() does.
547  * It then passes control to snstart to handle any other queued
548  * packets.
549  */
550 static void
551 snresume(struct ifnet *ifp)
552 {
553 	struct sn_softc *sc = ifp->if_softc;
554 	u_int  len;
555 	struct mbuf *m;
556 	struct mbuf    *top;
557 	int             pad;
558 	int             mask;
559 	u_short         length;
560 	u_short         numPages;
561 	u_short         pages_wanted;
562 	u_char          packet_no;
563 
564 	if (sc->pages_wanted < 0)
565 		return;
566 
567 	pages_wanted = sc->pages_wanted;
568 	sc->pages_wanted = -1;
569 
570 	/*
571 	 * Sneak a peek at the next packet
572 	 */
573 	m = ifq_dequeue(&ifp->if_snd);
574 	if (m == NULL) {
575 		kprintf("%s: snresume() with nothing to send\n",
576 			ifp->if_xname);
577 		return;
578 	}
579 
580 	/*
581 	 * Compute the frame length and set pad to give an overall even
582 	 * number of bytes.  Below we assume that the packet length is even.
583 	 */
584 	for (len = 0, top = m; m; m = m->m_next)
585 		len += m->m_len;
586 
587 	pad = (len & 1);
588 
589 	/*
590 	 * We drop packets that are too large. Perhaps we should truncate
591 	 * them instead?
592 	 */
593 	if (len + pad > ETHER_MAX_LEN - ETHER_CRC_LEN) {
594 		kprintf("%s: large packet discarded (B)\n", ifp->if_xname);
595 		IFNET_STAT_INC(ifp, oerrors, 1);
596 		m_freem(top);
597 		return;
598 	}
599 #ifdef SW_PAD
600 
601 	/*
602 	 * If HW padding is not turned on, then pad to ETHER_MIN_LEN.
603 	 */
604 	if (len < ETHER_MIN_LEN - ETHER_CRC_LEN)
605 		pad = ETHER_MIN_LEN - ETHER_CRC_LEN - len;
606 
607 #endif	/* SW_PAD */
608 
609 	length = pad + len;
610 
611 
612 	/*
613 	 * The MMU wants the number of pages to be the number of 256 byte
614 	 * 'pages', minus 1 (A packet can't ever have 0 pages. We also
615 	 * include space for the status word, byte count and control bytes in
616 	 * the allocation request.
617 	 */
618 	numPages = (length + 6) >> 8;
619 
620 
621 	SMC_SELECT_BANK(2);
622 
623 	/*
624 	 * The memory allocation completed.  Check the results. If it failed,
625 	 * we simply set a watchdog timer and hope for the best.
626 	 */
627 	packet_no = inb(BASE + ALLOC_RESULT_REG_B);
628 	if (packet_no & ARR_FAILED) {
629 		kprintf("%s: Memory allocation failed.  Weird.\n", ifp->if_xname);
630 		ifp->if_timer = 1;
631 		ifq_prepend(&ifp->if_snd, top);
632 		goto try_start;
633 	}
634 	/*
635 	 * We have a packet number, so tell the card to use it.
636 	 */
637 	outb(BASE + PACKET_NUM_REG_B, packet_no);
638 
639 	/*
640 	 * Now, numPages should match the pages_wanted recorded when the
641 	 * memory allocation was initiated.
642 	 */
643 	if (pages_wanted != numPages) {
644 		kprintf("%s: memory allocation wrong size.  Weird.\n", ifp->if_xname);
645 		/*
646 		 * If the allocation was the wrong size we simply release the
647 		 * memory once it is granted. Wait for the MMU to be un-busy.
648 		 */
649 		while (inw(BASE + MMU_CMD_REG_W) & MMUCR_BUSY)	/* NOTHING */
650 			;
651 		outw(BASE + MMU_CMD_REG_W, MMUCR_FREEPKT);
652 
653 		ifq_prepend(&ifp->if_snd, top);
654 		return;
655 	}
656 	/*
657 	 * Point to the beginning of the packet
658 	 */
659 	outw(BASE + POINTER_REG_W, PTR_AUTOINC | 0x0000);
660 
661 	/*
662 	 * Send the packet length (+6 for status, length and control byte)
663 	 * and the status word (set to zeros)
664 	 */
665 	outw(BASE + DATA_REG_W, 0);
666 	outb(BASE + DATA_REG_B, (length + 6) & 0xFF);
667 	outb(BASE + DATA_REG_B, (length + 6) >> 8);
668 
669 	/*
670 	 * Push out the data to the card.
671 	 */
672 	for (m = top; m != NULL; m = m->m_next) {
673 
674 		/*
675 		 * Push out words.
676 		 */
677 		outsw(BASE + DATA_REG_W, mtod(m, caddr_t), m->m_len / 2);
678 
679 		/*
680 		 * Push out remaining byte.
681 		 */
682 		if (m->m_len & 1)
683 			outb(BASE + DATA_REG_B, *(mtod(m, caddr_t) + m->m_len - 1));
684 	}
685 
686 	/*
687 	 * Push out padding.
688 	 */
689 	while (pad > 1) {
690 		outw(BASE + DATA_REG_W, 0);
691 		pad -= 2;
692 	}
693 	if (pad)
694 		outb(BASE + DATA_REG_B, 0);
695 
696 	/*
697 	 * Push out control byte and unused packet byte The control byte is 0
698 	 * meaning the packet is even lengthed and no special CRC handling is
699 	 * desired.
700 	 */
701 	outw(BASE + DATA_REG_W, 0);
702 
703 	/*
704 	 * Enable the interrupts and let the chipset deal with it Also set a
705 	 * watchdog in case we miss the interrupt.
706 	 */
707 	mask = inb(BASE + INTR_MASK_REG_B) | (IM_TX_INT | IM_TX_EMPTY_INT);
708 	outb(BASE + INTR_MASK_REG_B, mask);
709 	sc->intr_mask = mask;
710 	outw(BASE + MMU_CMD_REG_W, MMUCR_ENQUEUE);
711 
712 	BPF_MTAP(ifp, top);
713 
714 	IFNET_STAT_INC(ifp, opackets, 1);
715 	m_freem(top);
716 
717 try_start:
718 
719 	/*
720 	 * Now pass control to snstart() to queue any additional packets
721 	 */
722 	ifq_clr_oactive(&ifp->if_snd);
723 	if_devstart(ifp);
724 
725 	/*
726 	 * We've sent something, so we're active.  Set a watchdog in case the
727 	 * TX_EMPTY interrupt is lost.
728 	 */
729 	ifq_set_oactive(&ifp->if_snd);
730 	ifp->if_timer = 1;
731 }
732 
733 
734 void
735 sn_intr(void *arg)
736 {
737 	int             status, interrupts;
738 	struct sn_softc *sc = (struct sn_softc *) arg;
739 	struct ifnet   *ifp = &sc->arpcom.ac_if;
740 
741 	/*
742 	 * Chip state registers
743 	 */
744 	u_char          mask;
745 	u_char          packet_no;
746 	u_short         tx_status;
747 	u_short         card_stats;
748 
749 	/*
750 	 * Clear the watchdog.
751 	 */
752 	ifp->if_timer = 0;
753 
754 	SMC_SELECT_BANK(2);
755 
756 	/*
757 	 * Obtain the current interrupt mask and clear the hardware mask
758 	 * while servicing interrupts.
759 	 */
760 	mask = inb(BASE + INTR_MASK_REG_B);
761 	outb(BASE + INTR_MASK_REG_B, 0x00);
762 
763 	/*
764 	 * Get the set of interrupts which occurred and eliminate any which
765 	 * are masked.
766 	 */
767 	interrupts = inb(BASE + INTR_STAT_REG_B);
768 	status = interrupts & mask;
769 
770 	/*
771 	 * Now, process each of the interrupt types.
772 	 */
773 
774 	/*
775 	 * Receive Overrun.
776 	 */
777 	if (status & IM_RX_OVRN_INT) {
778 
779 		/*
780 		 * Acknowlege Interrupt
781 		 */
782 		SMC_SELECT_BANK(2);
783 		outb(BASE + INTR_ACK_REG_B, IM_RX_OVRN_INT);
784 
785 		IFNET_STAT_INC(&sc->arpcom.ac_if, ierrors, 1);
786 	}
787 	/*
788 	 * Got a packet.
789 	 */
790 	if (status & IM_RCV_INT) {
791 #if 1
792 		int             packet_number;
793 
794 		SMC_SELECT_BANK(2);
795 		packet_number = inw(BASE + FIFO_PORTS_REG_W);
796 
797 		if (packet_number & FIFO_REMPTY) {
798 
799 			/*
800 			 * we got called , but nothing was on the FIFO
801 			 */
802 			kprintf("sn: Receive interrupt with nothing on FIFO\n");
803 
804 			goto out;
805 		}
806 #endif
807 		snread(ifp);
808 	}
809 	/*
810 	 * An on-card memory allocation came through.
811 	 */
812 	if (status & IM_ALLOC_INT) {
813 
814 		/*
815 		 * Disable this interrupt.
816 		 */
817 		mask &= ~IM_ALLOC_INT;
818 		ifq_clr_oactive(&sc->arpcom.ac_if.if_snd);
819 		snresume(&sc->arpcom.ac_if);
820 	}
821 	/*
822 	 * TX Completion.  Handle a transmit error message. This will only be
823 	 * called when there is an error, because of the AUTO_RELEASE mode.
824 	 */
825 	if (status & IM_TX_INT) {
826 
827 		/*
828 		 * Acknowlege Interrupt
829 		 */
830 		SMC_SELECT_BANK(2);
831 		outb(BASE + INTR_ACK_REG_B, IM_TX_INT);
832 
833 		packet_no = inw(BASE + FIFO_PORTS_REG_W);
834 		packet_no &= FIFO_TX_MASK;
835 
836 		/*
837 		 * select this as the packet to read from
838 		 */
839 		outb(BASE + PACKET_NUM_REG_B, packet_no);
840 
841 		/*
842 		 * Position the pointer to the first word from this packet
843 		 */
844 		outw(BASE + POINTER_REG_W, PTR_AUTOINC | PTR_READ | 0x0000);
845 
846 		/*
847 		 * Fetch the TX status word.  The value found here will be a
848 		 * copy of the EPH_STATUS_REG_W at the time the transmit
849 		 * failed.
850 		 */
851 		tx_status = inw(BASE + DATA_REG_W);
852 
853 		if (tx_status & EPHSR_TX_SUC) {
854 			device_printf(sc->dev,
855 			    "Successful packet caused interrupt\n");
856 		} else {
857 			IFNET_STAT_INC(&sc->arpcom.ac_if, oerrors, 1);
858 		}
859 
860 		if (tx_status & EPHSR_LATCOL)
861 			IFNET_STAT_INC(&sc->arpcom.ac_if, collisions, 1);
862 
863 		/*
864 		 * Some of these errors will have disabled transmit.
865 		 * Re-enable transmit now.
866 		 */
867 		SMC_SELECT_BANK(0);
868 
869 #ifdef SW_PAD
870 		outw(BASE + TXMIT_CONTROL_REG_W, TCR_ENABLE);
871 #else
872 		outw(BASE + TXMIT_CONTROL_REG_W, TCR_ENABLE | TCR_PAD_ENABLE);
873 #endif	/* SW_PAD */
874 
875 		/*
876 		 * kill the failed packet. Wait for the MMU to be un-busy.
877 		 */
878 		SMC_SELECT_BANK(2);
879 		while (inw(BASE + MMU_CMD_REG_W) & MMUCR_BUSY)	/* NOTHING */
880 			;
881 		outw(BASE + MMU_CMD_REG_W, MMUCR_FREEPKT);
882 
883 		/*
884 		 * Attempt to queue more transmits.
885 		 */
886 		ifq_clr_oactive(&sc->arpcom.ac_if.if_snd);
887 		if_devstart(&sc->arpcom.ac_if);
888 	}
889 	/*
890 	 * Transmit underrun.  We use this opportunity to update transmit
891 	 * statistics from the card.
892 	 */
893 	if (status & IM_TX_EMPTY_INT) {
894 
895 		/*
896 		 * Acknowlege Interrupt
897 		 */
898 		SMC_SELECT_BANK(2);
899 		outb(BASE + INTR_ACK_REG_B, IM_TX_EMPTY_INT);
900 
901 		/*
902 		 * Disable this interrupt.
903 		 */
904 		mask &= ~IM_TX_EMPTY_INT;
905 
906 		SMC_SELECT_BANK(0);
907 		card_stats = inw(BASE + COUNTER_REG_W);
908 
909 		/*
910 		 * Single collisions
911 		 */
912 		IFNET_STAT_INC(&sc->arpcom.ac_if, collisions,
913 		    card_stats & ECR_COLN_MASK);
914 
915 		/*
916 		 * Multiple collisions
917 		 */
918 		IFNET_STAT_INC(&sc->arpcom.ac_if, collisions,
919 		    (card_stats & ECR_MCOLN_MASK) >> 4);
920 
921 		SMC_SELECT_BANK(2);
922 
923 		/*
924 		 * Attempt to enqueue some more stuff.
925 		 */
926 		ifq_clr_oactive(&sc->arpcom.ac_if.if_snd);
927 		if_devstart(&sc->arpcom.ac_if);
928 	}
929 	/*
930 	 * Some other error.  Try to fix it by resetting the adapter.
931 	 */
932 	if (status & IM_EPH_INT) {
933 		snstop(sc);
934 		sninit(sc);
935 	}
936 
937 out:
938 	/*
939 	 * Handled all interrupt sources.
940 	 */
941 
942 	SMC_SELECT_BANK(2);
943 
944 	/*
945 	 * Reestablish interrupts from mask which have not been deselected
946 	 * during this interrupt.  Note that the hardware mask, which was set
947 	 * to 0x00 at the start of this service routine, may have been
948 	 * updated by one or more of the interrupt handers and we must let
949 	 * those new interrupts stay enabled here.
950 	 */
951 	mask |= inb(BASE + INTR_MASK_REG_B);
952 	outb(BASE + INTR_MASK_REG_B, mask);
953 	sc->intr_mask = mask;
954 }
955 
956 void
957 snread(struct ifnet *ifp)
958 {
959         struct sn_softc *sc = ifp->if_softc;
960 	struct mbuf    *m;
961 	short           status;
962 	int             packet_number;
963 	u_short         packet_length;
964 	u_char         *data;
965 
966 	SMC_SELECT_BANK(2);
967 #if 0
968 	packet_number = inw(BASE + FIFO_PORTS_REG_W);
969 
970 	if (packet_number & FIFO_REMPTY) {
971 
972 		/*
973 		 * we got called , but nothing was on the FIFO
974 		 */
975 		kprintf("sn: Receive interrupt with nothing on FIFO\n");
976 		return;
977 	}
978 #endif
979 read_another:
980 
981 	/*
982 	 * Start reading from the start of the packet. Since PTR_RCV is set,
983 	 * packet number is found in FIFO_PORTS_REG_W, FIFO_RX_MASK.
984 	 */
985 	outw(BASE + POINTER_REG_W, PTR_READ | PTR_RCV | PTR_AUTOINC | 0x0000);
986 
987 	/*
988 	 * First two words are status and packet_length
989 	 */
990 	status = inw(BASE + DATA_REG_W);
991 	packet_length = inw(BASE + DATA_REG_W) & RLEN_MASK;
992 
993 	/*
994 	 * The packet length contains 3 extra words: status, length, and a
995 	 * extra word with the control byte.
996 	 */
997 	packet_length -= 6;
998 
999 	/*
1000 	 * Account for receive errors and discard.
1001 	 */
1002 	if (status & RS_ERRORS) {
1003 		IFNET_STAT_INC(ifp, ierrors, 1);
1004 		goto out;
1005 	}
1006 	/*
1007 	 * A packet is received.
1008 	 */
1009 
1010 	/*
1011 	 * Adjust for odd-length packet.
1012 	 */
1013 	if (status & RS_ODDFRAME)
1014 		packet_length++;
1015 
1016 	/*
1017 	 * Allocate a header mbuf from the kernel.
1018 	 */
1019 	MGETHDR(m, MB_DONTWAIT, MT_DATA);
1020 	if (m == NULL)
1021 		goto out;
1022 
1023 	m->m_pkthdr.rcvif = ifp;
1024 	m->m_pkthdr.len = m->m_len = packet_length;
1025 
1026 	/*
1027 	 * Attach an mbuf cluster
1028 	 */
1029 	MCLGET(m, MB_DONTWAIT);
1030 
1031 	/*
1032 	 * Insist on getting a cluster
1033 	 */
1034 	if ((m->m_flags & M_EXT) == 0) {
1035 		m_freem(m);
1036 		IFNET_STAT_INC(ifp, ierrors, 1);
1037 		kprintf("sn: snread() kernel memory allocation problem\n");
1038 		goto out;
1039 	}
1040 
1041 	/*
1042 	 * Get packet, including link layer address, from interface.
1043 	 */
1044 
1045 	data = mtod(m, u_char *);
1046 	insw(BASE + DATA_REG_W, data, packet_length >> 1);
1047 	if (packet_length & 1) {
1048 		data += packet_length & ~1;
1049 		*data = inb(BASE + DATA_REG_B);
1050 	}
1051 	IFNET_STAT_INC(ifp, ipackets, 1);
1052 
1053 	m->m_pkthdr.len = m->m_len = packet_length;
1054 
1055 	ifp->if_input(ifp, m);
1056 
1057 out:
1058 
1059 	/*
1060 	 * Error or good, tell the card to get rid of this packet Wait for
1061 	 * the MMU to be un-busy.
1062 	 */
1063 	SMC_SELECT_BANK(2);
1064 	while (inw(BASE + MMU_CMD_REG_W) & MMUCR_BUSY)	/* NOTHING */
1065 		;
1066 	outw(BASE + MMU_CMD_REG_W, MMUCR_RELEASE);
1067 
1068 	/*
1069 	 * Check whether another packet is ready
1070 	 */
1071 	packet_number = inw(BASE + FIFO_PORTS_REG_W);
1072 	if (packet_number & FIFO_REMPTY) {
1073 		return;
1074 	}
1075 	goto read_another;
1076 }
1077 
1078 
1079 /*
1080  * Handle IOCTLS.  This function is completely stolen from if_ep.c
1081  * As with its progenitor, it does not handle hardware address
1082  * changes.
1083  */
1084 static int
1085 snioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
1086 {
1087 	struct sn_softc *sc = ifp->if_softc;
1088 	int error = 0;
1089 
1090 	switch (cmd) {
1091 	case SIOCSIFFLAGS:
1092 		if ((ifp->if_flags & IFF_UP) == 0 && ifp->if_flags & IFF_RUNNING) {
1093 			ifp->if_flags &= ~IFF_RUNNING;
1094 			snstop(sc);
1095 			break;
1096 		} else {
1097 			/* reinitialize card on any parameter change */
1098 			sninit(sc);
1099 			break;
1100 		}
1101 		break;
1102 
1103 #ifdef notdef
1104 	case SIOCGHWADDR:
1105 		bcopy((caddr_t) sc->sc_addr, (caddr_t) & ifr->ifr_data,
1106 		      sizeof(sc->sc_addr));
1107 		break;
1108 #endif
1109 
1110 	case SIOCADDMULTI:
1111 	    /* update multicast filter list. */
1112 	    sn_setmcast(sc);
1113 	    error = 0;
1114 	    break;
1115 	case SIOCDELMULTI:
1116 	    /* update multicast filter list. */
1117 	    sn_setmcast(sc);
1118 	    error = 0;
1119 	    break;
1120 	default:
1121 		error = ether_ioctl(ifp, cmd, data);
1122 		break;
1123 	}
1124 
1125 	return (error);
1126 }
1127 
1128 void
1129 snreset(struct sn_softc *sc)
1130 {
1131 	snstop(sc);
1132 	sninit(sc);
1133 }
1134 
1135 void
1136 snwatchdog(struct ifnet *ifp)
1137 {
1138 	sn_intr(ifp->if_softc);
1139 }
1140 
1141 
1142 /* 1. zero the interrupt mask
1143  * 2. clear the enable receive flag
1144  * 3. clear the enable xmit flags
1145  */
1146 void
1147 snstop(struct sn_softc *sc)
1148 {
1149 
1150 	struct ifnet   *ifp = &sc->arpcom.ac_if;
1151 
1152 	/*
1153 	 * Clear interrupt mask; disable all interrupts.
1154 	 */
1155 	SMC_SELECT_BANK(2);
1156 	outb(BASE + INTR_MASK_REG_B, 0x00);
1157 
1158 	/*
1159 	 * Disable transmitter and Receiver
1160 	 */
1161 	SMC_SELECT_BANK(0);
1162 	outw(BASE + RECV_CONTROL_REG_W, 0x0000);
1163 	outw(BASE + TXMIT_CONTROL_REG_W, 0x0000);
1164 
1165 	/*
1166 	 * Cancel watchdog.
1167 	 */
1168 	ifp->if_timer = 0;
1169 }
1170 
1171 
1172 int
1173 sn_activate(device_t dev)
1174 {
1175 	struct sn_softc *sc = device_get_softc(dev);
1176 
1177 	sc->port_rid = 0;
1178 	sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->port_rid,
1179 	    0, ~0, SMC_IO_EXTENT, RF_ACTIVE);
1180 	if (!sc->port_res) {
1181 #ifdef SN_DEBUG
1182 		device_printf(dev, "Cannot allocate ioport\n");
1183 #endif
1184 		return ENOMEM;
1185 	}
1186 
1187 	sc->irq_rid = 0;
1188 	sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->irq_rid,
1189 	    RF_ACTIVE);
1190 	if (!sc->irq_res) {
1191 #ifdef SN_DEBUG
1192 		device_printf(dev, "Cannot allocate irq\n");
1193 #endif
1194 		sn_deactivate(dev);
1195 		return ENOMEM;
1196 	}
1197 
1198 	sc->sn_io_addr = rman_get_start(sc->port_res);
1199 	return (0);
1200 }
1201 
1202 void
1203 sn_deactivate(device_t dev)
1204 {
1205 	struct sn_softc *sc = device_get_softc(dev);
1206 
1207 	if (sc->port_res)
1208 		bus_release_resource(dev, SYS_RES_IOPORT, sc->port_rid,
1209 		    sc->port_res);
1210 	sc->port_res = 0;
1211 	if (sc->irq_res)
1212 		bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid,
1213 		    sc->irq_res);
1214 	sc->irq_res = 0;
1215 	return;
1216 }
1217 
1218 /*
1219  * Function: sn_probe( device_t dev, int pccard )
1220  *
1221  * Purpose:
1222  *      Tests to see if a given ioaddr points to an SMC9xxx chip.
1223  *      Tries to cause as little damage as possible if it's not a SMC chip.
1224  *      Returns a 0 on success
1225  *
1226  * Algorithm:
1227  *      (1) see if the high byte of BANK_SELECT is 0x33
1228  *      (2) compare the ioaddr with the base register's address
1229  *      (3) see if I recognize the chip ID in the appropriate register
1230  *
1231  *
1232  */
1233 int
1234 sn_probe(device_t dev, int pccard)
1235 {
1236 	struct sn_softc *sc = device_get_softc(dev);
1237 	u_int           bank;
1238 	u_short         revision_register;
1239 	u_short         base_address_register;
1240 	u_short		ioaddr;
1241 	int		err;
1242 
1243 	if ((err = sn_activate(dev)) != 0)
1244 		return err;
1245 
1246 	ioaddr = sc->sn_io_addr;
1247 
1248 	/*
1249 	 * First, see if the high byte is 0x33
1250 	 */
1251 	bank = inw(ioaddr + BANK_SELECT_REG_W);
1252 	if ((bank & BSR_DETECT_MASK) != BSR_DETECT_VALUE) {
1253 #ifdef	SN_DEBUG
1254 		device_printf(dev, "test1 failed\n");
1255 #endif
1256 		goto error;
1257 	}
1258 	/*
1259 	 * The above MIGHT indicate a device, but I need to write to further
1260 	 * test this.  Go to bank 0, then test that the register still
1261 	 * reports the high byte is 0x33.
1262 	 */
1263 	outw(ioaddr + BANK_SELECT_REG_W, 0x0000);
1264 	bank = inw(ioaddr + BANK_SELECT_REG_W);
1265 	if ((bank & BSR_DETECT_MASK) != BSR_DETECT_VALUE) {
1266 #ifdef	SN_DEBUG
1267 		device_printf(dev, "test2 failed\n");
1268 #endif
1269 		goto error;
1270 	}
1271 	/*
1272 	 * well, we've already written once, so hopefully another time won't
1273 	 * hurt.  This time, I need to switch the bank register to bank 1, so
1274 	 * I can access the base address register.  The contents of the
1275 	 * BASE_ADDR_REG_W register, after some jiggery pokery, is expected
1276 	 * to match the I/O port address where the adapter is being probed.
1277 	 */
1278 	outw(ioaddr + BANK_SELECT_REG_W, 0x0001);
1279 	base_address_register = inw(ioaddr + BASE_ADDR_REG_W);
1280 
1281 	/*
1282 	 * This test is nonsence on PC-card architecture, so if
1283 	 * pccard == 1, skip this test. (hosokawa)
1284 	 */
1285 	if (!pccard && (ioaddr != (base_address_register >> 3 & 0x3E0))) {
1286 
1287 		/*
1288 		 * Well, the base address register didn't match.  Must not
1289 		 * have been a SMC chip after all.
1290 		 */
1291 		/*
1292 		 * kprintf("sn: ioaddr %x doesn't match card configuration
1293 		 * (%x)\n", ioaddr, base_address_register >> 3 & 0x3E0 );
1294 		 */
1295 
1296 #ifdef	SN_DEBUG
1297 		device_printf(dev, "test3 failed ioaddr = 0x%x, "
1298 		    "base_address_register = 0x%x\n", ioaddr,
1299 		    base_address_register >> 3 & 0x3E0);
1300 #endif
1301 		goto error;
1302 	}
1303 	/*
1304 	 * Check if the revision register is something that I recognize.
1305 	 * These might need to be added to later, as future revisions could
1306 	 * be added.
1307 	 */
1308 	outw(ioaddr + BANK_SELECT_REG_W, 0x3);
1309 	revision_register = inw(ioaddr + REVISION_REG_W);
1310 	if (!chip_ids[(revision_register >> 4) & 0xF]) {
1311 
1312 		/*
1313 		 * I don't regonize this chip, so...
1314 		 */
1315 #ifdef	SN_DEBUG
1316 		device_printf(dev, "test4 failed\n");
1317 #endif
1318 		goto error;
1319 	}
1320 	/*
1321 	 * at this point I'll assume that the chip is an SMC9xxx. It might be
1322 	 * prudent to check a listing of MAC addresses against the hardware
1323 	 * address, or do some other tests.
1324 	 */
1325 	sn_deactivate(dev);
1326 	return 0;
1327  error:
1328 	sn_deactivate(dev);
1329 	return ENXIO;
1330 }
1331 
1332 #define MCFSZ 8
1333 
1334 static void
1335 sn_setmcast(struct sn_softc *sc)
1336 {
1337 	struct ifnet *ifp = (struct ifnet *)sc;
1338 	int flags;
1339 
1340 	/*
1341 	 * Set the receiver filter.  We want receive enabled and auto strip
1342 	 * of CRC from received packet.  If we are promiscuous then set that
1343 	 * bit too.
1344 	 */
1345 	flags = RCR_ENABLE | RCR_STRIP_CRC;
1346 
1347 	if (ifp->if_flags & IFF_PROMISC) {
1348 		flags |= RCR_PROMISC | RCR_ALMUL;
1349 	} else if (ifp->if_flags & IFF_ALLMULTI) {
1350 		flags |= RCR_ALMUL;
1351 	} else {
1352 		u_char mcf[MCFSZ];
1353 		if (sn_getmcf(&sc->arpcom, mcf)) {
1354 			/* set filter */
1355 			SMC_SELECT_BANK(3);
1356 			outw(BASE + MULTICAST1_REG_W,
1357 			    ((u_short)mcf[1] << 8) |  mcf[0]);
1358 			outw(BASE + MULTICAST2_REG_W,
1359 			    ((u_short)mcf[3] << 8) |  mcf[2]);
1360 			outw(BASE + MULTICAST3_REG_W,
1361 			    ((u_short)mcf[5] << 8) |  mcf[4]);
1362 			outw(BASE + MULTICAST4_REG_W,
1363 			    ((u_short)mcf[7] << 8) |  mcf[6]);
1364 		} else {
1365 			flags |= RCR_ALMUL;
1366 		}
1367 	}
1368 	SMC_SELECT_BANK(0);
1369 	outw(BASE + RECV_CONTROL_REG_W, flags);
1370 }
1371 
1372 static int
1373 sn_getmcf(struct arpcom *ac, u_char *mcf)
1374 {
1375 	int i;
1376 	u_int index, index2;
1377 	u_char *af = mcf;
1378 	struct ifmultiaddr *ifma;
1379 
1380 	bzero(mcf, MCFSZ);
1381 
1382 	TAILQ_FOREACH(ifma, &ac->ac_if.if_multiaddrs, ifma_link) {
1383 	    if (ifma->ifma_addr->sa_family != AF_LINK)
1384 		return 0;
1385 	    index = smc_crc(LLADDR((struct sockaddr_dl *)ifma->ifma_addr)) & 0x3f;
1386 	    index2 = 0;
1387 	    for (i = 0; i < 6; i++) {
1388 		index2 <<= 1;
1389 		index2 |= (index & 0x01);
1390 		index >>= 1;
1391 	    }
1392 	    af[index2 >> 3] |= 1 << (index2 & 7);
1393 	}
1394 	return 1;  /* use multicast filter */
1395 }
1396 
1397 static u_int
1398 smc_crc(u_char *s)
1399 {
1400 	int perByte;
1401 	int perBit;
1402 	const u_int poly = 0xedb88320;
1403 	u_int v = 0xffffffff;
1404 	u_char c;
1405 
1406 	for (perByte = 0; perByte < ETHER_ADDR_LEN; perByte++) {
1407 		c = s[perByte];
1408 		for (perBit = 0; perBit < 8; perBit++) {
1409 			v = (v >> 1)^(((v ^ c) & 0x01) ? poly : 0);
1410 			c >>= 1;
1411 		}
1412 	}
1413 	return v;
1414 }
1415