xref: /netbsd-src/sys/dev/ic/ne2000.c (revision f5d3fbbc6ff4a77159fb268d247bd94cb7d7e332)
1 /*	$NetBSD: ne2000.c,v 1.3 1997/10/15 01:15:51 enami Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center.
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. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the NetBSD
22  *	Foundation, Inc. and its contributors.
23  * 4. Neither the name of The NetBSD Foundation nor the names of its
24  *    contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37  * POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 /*
41  * Device driver for National Semiconductor DS8390/WD83C690 based ethernet
42  * adapters.
43  *
44  * Copyright (c) 1994, 1995 Charles M. Hannum.  All rights reserved.
45  *
46  * Copyright (C) 1993, David Greenman.  This software may be used, modified,
47  * copied, distributed, and sold, in both source and binary form provided that
48  * the above copyright and these terms are retained.  Under no circumstances is
49  * the author responsible for the proper functioning of this software, nor does
50  * the author assume any responsibility for damages incurred with its use.
51  */
52 
53 /*
54  * Common code shared by all NE2000-compatible Ethernet interfaces.
55  */
56 
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/device.h>
60 #include <sys/socket.h>
61 #include <sys/mbuf.h>
62 #include <sys/syslog.h>
63 
64 #include <net/if.h>
65 #include <net/if_dl.h>
66 #include <net/if_types.h>
67 
68 #include <net/if_ether.h>
69 
70 #include <machine/bus.h>
71 
72 #include <dev/ic/dp8390reg.h>
73 #include <dev/ic/dp8390var.h>
74 
75 #include <dev/ic/ne2000reg.h>
76 #include <dev/ic/ne2000var.h>
77 
78 struct cfdriver ne_cd = {
79 	NULL, "ne", DV_IFNET
80 };
81 
82 int	ne2000_write_mbuf __P((struct dp8390_softc *, struct mbuf *, int));
83 int	ne2000_ring_copy __P((struct dp8390_softc *, int, caddr_t, u_short));
84 void	ne2000_read_hdr __P((struct dp8390_softc *, int, struct dp8390_ring *));
85 int	ne2000_test_mem __P((struct dp8390_softc *));
86 
87 void	ne2000_writemem __P((bus_space_tag_t, bus_space_handle_t,
88 	    bus_space_tag_t, bus_space_handle_t, u_int8_t *, int, size_t, int));
89 void	ne2000_readmem __P((bus_space_tag_t, bus_space_handle_t,
90 	    bus_space_tag_t, bus_space_handle_t, int, u_int8_t *, size_t, int));
91 
92 void
93 ne2000_attach(nsc, myea)
94 	struct ne2000_softc *nsc;
95 	u_int8_t *myea;
96 {
97 	struct dp8390_softc *dsc = &nsc->sc_dp8390;
98 	bus_space_tag_t nict = dsc->sc_regt;
99 	bus_space_handle_t nich = dsc->sc_regh;
100 	bus_space_tag_t asict = nsc->sc_asict;
101 	bus_space_handle_t asich = nsc->sc_asich;
102 	u_int8_t romdata[16];
103 	int memsize, i, useword;
104 
105 	/*
106 	 * Detect it again; this gives us the memory size.
107 	 */
108 	nsc->sc_type = ne2000_detect(nict, nich, asict, asich);
109 	if (nsc->sc_type == 0) {
110 		printf("%s: where did the card go?\n", dsc->sc_dev.dv_xname);
111 		return;
112 	}
113 
114 	useword = (nsc->sc_type == NE2000_TYPE_NE2000);
115 
116 	dsc->cr_proto = ED_CR_RD2;
117 
118 	/*
119 	 * DCR gets:
120 	 *
121 	 *	FIFO threshold to 8, No auto-init Remote DMA,
122 	 *	byte order=80x86.
123 	 *
124 	 * NE1000 gets byte-wide DMA, NE2000 gets word-wide DMA.
125 	 */
126 	dsc->dcr_reg = ED_DCR_FT1 | ED_DCR_LS |
127 	    (nsc->sc_type == NE2000_TYPE_NE2000 ? ED_DCR_WTS : 0);
128 
129 	dsc->test_mem = ne2000_test_mem;
130 	dsc->ring_copy = ne2000_ring_copy;
131 	dsc->write_mbuf = ne2000_write_mbuf;
132 	dsc->read_hdr = ne2000_read_hdr;
133 
134 	/* Registers are linear. */
135 	for (i = 0; i < 16; i++)
136 		dsc->sc_reg_map[i] = i;
137 
138 	/*
139 	 * 8k of memory plus an additional 8k if an NE2000.
140 	 */
141 	memsize = 8192 + (nsc->sc_type == NE2000_TYPE_NE2000 ? 8192 : 0);
142 
143 	/*
144 	 * NIC memory doens't start at zero on an NE board.
145 	 * The start address is tied to the bus width.
146 	 * (It happens to be computed the same way as mem size.)
147 	 */
148 	dsc->mem_start = memsize;
149 
150 #ifdef GWETHER
151 	{
152 		int x, mstart = 0;
153 		int8_t pbuf0[ED_PAGE_SIZE], pbuf[ED_PAGE_SIZE],
154 		    tbuf[ED_PAGE_SIZE];
155 
156 		for (i = 0; i < ED_PAGE_SIZE; i++)
157 			pbuf0[i] = 0;
158 
159 		/* Search for the start of RAM. */
160 		for (x = 1; x < 256; x++) {
161 			ne2000_writemem(nict, nich, asict, asich, pbuf0,
162 			    x << ED_PAGE_SHIFT, ED_PAGE_SIZE, useword);
163 			ne2000_readmem(nict, nich, asict, asich,
164 			    x << ED_PAGE_SHIFT, tbuf, ED_PAGE_SIZE, useword);
165 			if (bcmp(pbuf0, tbuf, ED_PAGE_SIZE) == 0) {
166 				for (i = 0; i < ED_PAGE_SIZE; i++)
167 					pbuf[i] = 255 - x;
168 				ne2000_writemem(nict, nich, asict, asich,
169 				    pbuf, x << ED_PAGE_SHIFT, ED_PAGE_SIZE,
170 				    useword);
171 				ne2000_readmem(nict, nich, asict, asich,
172 				    x << ED_PAGE_SHIFT, tbuf, ED_PAGE_SIZE,
173 				    useword);
174 				if (bcmp(pbuf, tbuf, ED_PAGE_SIZE) == 0) {
175 					mstart = x << ED_PAGE_SHIFT;
176 					memsize = ED_PAGE_SIZE;
177 					break;
178 				}
179 			}
180 		}
181 
182 		if (mstart == 0) {
183 			printf("%s: cannot find start of RAM\n",
184 			    dsc->sc_dev.dv_xname);
185 			return;
186 		}
187 
188 		/* Search for the end of RAM. */
189 		for (++x; x < 256; x++) {
190 			ne2000_writemem(nict, nich, asict, asich, pbuf0,
191 			    x << ED_PAGE_SHIFT, ED_PAGE_SIZE, useword);
192 			ne2000_readmem(nict, nich, asict, asich,
193 			    x << ED_PAGE_SHIFT, tbuf, ED_PAGE_SIZE, useword);
194 			if (bcmp(pbuf0, tbuf, ED_PAGE_SIZE) == 0) {
195 				for (i = 0; i < ED_PAGE_SIZE; i++)
196 					pbuf[i] = 255 - x;
197 				ne2000_writemem(nict, nich, asict, asich,
198 				    pbuf, x << ED_PAGE_SHIFT, ED_PAGE_SIZE,
199 				    useword);
200 				ne2000_readmem(nict, nich, asict, asich,
201 				    x << ED_PAGE_SHIFT, tbuf, ED_PAGE_SIZE
202 				    useword);
203 				if (bcmp(pbuf, tbuf, ED_PAGE_SIZE) == 0)
204 					memsize += ED_PAGE_SIZE;
205 				else
206 					break;
207 			} else
208 				break;
209 		}
210 
211 		printf("%s: RAM start 0x%x, size %d\n",
212 		    dsc->sc_dev.dv_xname, mstart, msize);
213 
214 		dsc->mem_start = mstart;
215 	}
216 #endif /* GWETHER */
217 
218 	dsc->mem_size = memsize;
219 
220 	if (myea == NULL) {
221 		/* Read the station address. */
222 		ne2000_readmem(nict, nich, asict, asich, 0, romdata,
223 		    sizeof(romdata), useword);
224 		for (i = 0; i < ETHER_ADDR_LEN; i++)
225 			dsc->sc_enaddr[i] = romdata[i * (useword ? 2 : 1)];
226 	} else
227 		bcopy(myea, dsc->sc_enaddr, sizeof(dsc->sc_enaddr));
228 
229 	/* Clear any pending interrupts that might have occurred above. */
230 	bus_space_write_1(nict, nich, ED_P0_ISR, 0xff);
231 
232 	if (dp8390_config(dsc)) {
233 		printf("%s: setup failed\n", dsc->sc_dev.dv_xname);
234 		return;
235 	}
236 
237 	/*
238 	 * We need to compute mem_ring a bit differently; override the
239 	 * value set up in dp8390_config().
240 	 */
241 	dsc->mem_ring =
242 	    dsc->mem_start + ((dsc->txb_cnt * ED_TXBUF_SIZE) << ED_PAGE_SHIFT);
243 }
244 
245 /*
246  * Detect an NE-2000 or compatible.  Returns a model code.
247  */
248 int
249 ne2000_detect(nict, nich, asict, asich)
250 	bus_space_tag_t nict;
251 	bus_space_handle_t nich;
252 	bus_space_tag_t asict;
253 	bus_space_handle_t asich;
254 {
255 	static u_int8_t test_pattern[32] = "THIS is A memory TEST pattern";
256 	u_int8_t test_buffer[32], tmp;
257 	int i, rv = 0;
258 
259 	/* Reset the board. */
260 #ifdef GWETHER
261 	bus_space_write_1(asict, asich, NE2000_ASIC_RESET, 0);
262 	delay(200);
263 #endif /* GWETHER */
264 	tmp = bus_space_read_1(asict, asich, NE2000_ASIC_RESET);
265 	delay(10000);
266 
267 	/*
268 	 * I don't know if this is necessary; probably cruft leftover from
269 	 * Clarkson packet driver code. Doesn't do a thing on the boards I've
270 	 * tested. -DG [note that a outb(0x84, 0) seems to work here, and is
271 	 * non-invasive...but some boards don't seem to reset and I don't have
272 	 * complete documentation on what the 'right' thing to do is...so we do
273 	 * the invasive thing for now.  Yuck.]
274 	 */
275 	bus_space_write_1(asict, asich, NE2000_ASIC_RESET, tmp);
276 	delay(5000);
277 
278 	/*
279 	 * This is needed because some NE clones apparently don't reset the
280 	 * NIC properly (or the NIC chip doesn't reset fully on power-up).
281 	 * XXX - this makes the probe invasive!  Done against my better
282 	 * judgement.  -DLG
283 	 */
284 	bus_space_write_1(nict, nich, ED_P0_CR,
285 	    ED_CR_RD2 | ED_CR_PAGE_0 | ED_CR_STP);
286 
287 	delay(5000);
288 
289 	tmp = bus_space_read_1(nict, nich, ED_P0_CR);
290 	if ((tmp & (ED_CR_RD2 | ED_CR_TXP | ED_CR_STA | ED_CR_STP)) !=
291 	    (ED_CR_RD2 | ED_CR_STP))
292 		goto out;
293 
294 	bus_space_write_1(nict, nich,
295 	    ED_P0_CR, ED_CR_RD2 | ED_CR_PAGE_0 | ED_CR_STA);
296 
297 	for (i = 0; i < 100; i++) {
298 		if ((bus_space_read_1(nict, nich, ED_P0_ISR) & ED_ISR_RST) ==
299 		    ED_ISR_RST) {
300 			/* Ack the reset bit. */
301 			bus_space_write_1(nict, nich, ED_P0_ISR, ED_ISR_RST);
302 			break;
303 		}
304 		delay(100);
305 	}
306 
307 #if 0
308 	/* XXX */
309 	if (i == 100)
310 		goto out;
311 #endif
312 
313 	/*
314 	 * Test the ability to read and write to the NIC memory.  This has
315 	 * the side effect of determining if this is an NE1000 or an NE2000.
316 	 */
317 
318 	/*
319 	 * This prevents packets from being stored in the NIC memory when
320 	 * the readmem routine turns on the start bit in the CR.
321 	 */
322 	bus_space_write_1(nict, nich, ED_P0_RCR, ED_RCR_MON);
323 
324 	/* Temporarily initialize DCR for byte operations. */
325 	bus_space_write_1(nict, nich, ED_P0_DCR, ED_DCR_FT1 | ED_DCR_LS);
326 
327 	bus_space_write_1(nict, nich, ED_P0_PSTART, 8192 >> ED_PAGE_SHIFT);
328 	bus_space_write_1(nict, nich, ED_P0_PSTOP, 16384 >> ED_PAGE_SHIFT);
329 
330 	/*
331 	 * Write a test pattern in byte mode.  If this fails, then there
332 	 * probably isn't any memory at 8k - which likely means that the
333 	 * board is an NE2000.
334 	 */
335 	ne2000_writemem(nict, nich, asict, asich, test_pattern, 8192,
336 	    sizeof(test_pattern), 0);
337 	ne2000_readmem(nict, nich, asict, asich, 8192, test_buffer,
338 	    sizeof(test_buffer), 0);
339 
340 	if (bcmp(test_pattern, test_buffer, sizeof(test_pattern))) {
341 		/* not an NE1000 - try NE2000 */
342 		bus_space_write_1(nict, nich, ED_P0_DCR,
343 		    ED_DCR_WTS | ED_DCR_FT1 | ED_DCR_LS);
344 		bus_space_write_1(nict, nich, ED_P0_PSTART,
345 		    16384 >> ED_PAGE_SHIFT);
346 		bus_space_write_1(nict, nich, ED_P0_PSTOP,
347 		    32768 >> ED_PAGE_SHIFT);
348 
349 		/*
350 		 * Write the test pattern in word mode.  If this also fails,
351 		 * then we don't know what this board is.
352 		 */
353 		ne2000_writemem(nict, nich, asict, asich, test_pattern, 16384,
354 		    sizeof(test_pattern), 1);
355 		ne2000_readmem(nict, nich, asict, asich, 16384, test_buffer,
356 		    sizeof(test_buffer), 1);
357 
358 		if (bcmp(test_pattern, test_buffer, sizeof(test_pattern)))
359 			goto out;	/* not an NE2000 either */
360 
361 		rv = NE2000_TYPE_NE2000;
362 	} else {
363 		/* We're an NE1000. */
364 		rv = NE2000_TYPE_NE1000;
365 	}
366 
367 	/* Clear any pending interrupts that might have occurred above. */
368 	bus_space_write_1(nict, nich, ED_P0_ISR, 0xff);
369 
370  out:
371 	return (rv);
372 }
373 
374 /*
375  * Write an mbuf chain to the destination NIC memory address using programmed
376  * I/O.
377  */
378 int
379 ne2000_write_mbuf(sc, m, buf)
380 	struct dp8390_softc *sc;
381 	struct mbuf *m;
382 	int buf;
383 {
384 	struct ne2000_softc *nsc = (struct ne2000_softc *)sc;
385 	bus_space_tag_t nict = sc->sc_regt;
386 	bus_space_handle_t nich = sc->sc_regh;
387 	bus_space_tag_t asict = nsc->sc_asict;
388 	bus_space_handle_t asich = nsc->sc_asich;
389 	int savelen;
390 	int maxwait = 100;	/* about 120us */
391 
392 	savelen = m->m_pkthdr.len;
393 
394 	/* Select page 0 registers. */
395 	bus_space_write_1(nict, nich, ED_P0_CR,
396 	    ED_CR_RD2 | ED_CR_PAGE_0 | ED_CR_STA);
397 
398 	/* Reset remote DMA complete flag. */
399 	bus_space_write_1(nict, nich, ED_P0_ISR, ED_ISR_RDC);
400 
401 	/* Set up DMA byte count. */
402 	bus_space_write_1(nict, nich, ED_P0_RBCR0, savelen);
403 	bus_space_write_1(nict, nich, ED_P0_RBCR1, savelen >> 8);
404 
405 	/* Set up destination address in NIC mem. */
406 	bus_space_write_1(nict, nich, ED_P0_RSAR0, buf);
407 	bus_space_write_1(nict, nich, ED_P0_RSAR1, buf >> 8);
408 
409 	/* Set remote DMA write. */
410 	bus_space_write_1(nict, nich,
411 	    ED_P0_CR, ED_CR_RD1 | ED_CR_PAGE_0 | ED_CR_STA);
412 
413 	/*
414 	 * Transfer the mbuf chain to the NIC memory.  NE2000 cards
415 	 * require that data be transferred as words, and only words,
416 	 * so that case requires some extra code to patch over odd-length
417 	 * mbufs.
418 	 */
419 	if (nsc->sc_type == NE2000_TYPE_NE1000) {
420 		/* NE1000s are easy. */
421 		for (; m != 0; m = m->m_next) {
422 			if (m->m_len) {
423 				bus_space_write_multi_1(asict, asich,
424 				    NE2000_ASIC_DATA, mtod(m, u_int8_t *),
425 				    m->m_len);
426 			}
427 		}
428 	} else {
429 		/* NE2000s are a bit trickier. */
430 		u_int8_t *data, savebyte[2];
431 		int l, wantbyte;
432 
433 		wantbyte = 0;
434 		for (; m != 0; m = m->m_next) {
435 			l = m->m_len;
436 			if (l == 0)
437 				continue;
438 			data = mtod(m, u_int8_t *);
439 			/* Finish the last word. */
440 			if (wantbyte) {
441 				savebyte[1] = *data;
442 				bus_space_write_2(asict, asich,
443 				    NE2000_ASIC_DATA, *(u_int16_t *)savebyte);
444 				data++;
445 				l--;
446 				wantbyte = 0;
447 			}
448 			/* Output contiguous words. */
449 			if (l > 1) {
450 				bus_space_write_multi_2(asict, asich,
451 				    NE2000_ASIC_DATA, (u_int16_t *)data,
452 				    l >> 1);
453 			}
454 			/* Save last byte, if necessary. */
455 			if (l & 1) {
456 				data += l & ~1;
457 				savebyte[0] = *data;
458 				wantbyte = 1;
459 			}
460 		}
461 
462 		if (wantbyte) {
463 			savebyte[1] = 0;
464 			bus_space_write_2(asict, asich, NE2000_ASIC_DATA,
465 			    *(u_int16_t *)savebyte);
466 		}
467 	}
468 
469 	/*
470 	 * Wait for remote DMA to complete.  This is necessary because on the
471 	 * transmit side, data is handled internally by the NIC in bursts, and
472 	 * we can't start another remote DMA until this one completes.  Not
473 	 * waiting causes really bad things to happen - like the NIC wedging
474 	 * the bus.
475 	 */
476 	while (((bus_space_read_1(nict, nich, ED_P0_ISR) & ED_ISR_RDC) !=
477 	    ED_ISR_RDC) && --maxwait);
478 
479 	if (maxwait == 0) {
480 		log(LOG_WARNING,
481 		    "%s: remote transmit DMA failed to complete\n",
482 		    sc->sc_dev.dv_xname);
483 		dp8390_reset(sc);
484 	}
485 
486 	return (savelen);
487 }
488 
489 /*
490  * Given a source and destination address, copy 'amout' of a packet from
491  * the ring buffer into a linear destination buffer.  Takes into account
492  * ring-wrap.
493  */
494 int
495 ne2000_ring_copy(sc, src, dst, amount)
496 	struct dp8390_softc *sc;
497 	int src;
498 	caddr_t dst;
499 	u_short amount;
500 {
501 	struct ne2000_softc *nsc = (struct ne2000_softc *)sc;
502 	bus_space_tag_t nict = sc->sc_regt;
503 	bus_space_handle_t nich = sc->sc_regh;
504 	bus_space_tag_t asict = nsc->sc_asict;
505 	bus_space_handle_t asich = nsc->sc_asich;
506 	u_short tmp_amount;
507 	int useword = (nsc->sc_type == NE2000_TYPE_NE2000);
508 
509 	/* Does copy wrap to lower addr in ring buffer? */
510 	if (src + amount > sc->mem_end) {
511 		tmp_amount = sc->mem_end - src;
512 
513 		/* Copy amount up to end of NIC memory. */
514 		ne2000_readmem(nict, nich, asict, asich, src,
515 		    (u_int8_t *)dst, tmp_amount, useword);
516 
517 		amount -= tmp_amount;
518 		src = sc->mem_ring;
519 		dst += tmp_amount;
520 	}
521 
522 	ne2000_readmem(nict, nich, asict, asich, src, (u_int8_t *)dst,
523 	    amount, useword);
524 
525 	return (src + amount);
526 }
527 
528 void
529 ne2000_read_hdr(sc, buf, hdr)
530 	struct dp8390_softc *sc;
531 	int buf;
532 	struct dp8390_ring *hdr;
533 {
534 	struct ne2000_softc *nsc = (struct ne2000_softc *)sc;
535 
536 	ne2000_readmem(sc->sc_regt, sc->sc_regh, nsc->sc_asict, nsc->sc_asich,
537 	    buf, (u_int8_t *)hdr, sizeof(struct dp8390_ring),
538 	    (nsc->sc_type == NE2000_TYPE_NE2000));
539 }
540 
541 int
542 ne2000_test_mem(sc)
543 	struct dp8390_softc *sc;
544 {
545 
546 	/* Noop. */
547 	return (0);
548 }
549 
550 /*
551  * Given a NIC memory source address and a host memory destination address,
552  * copy 'amount' from NIC to host using programmed i/o.  The 'amount' is
553  * rounded up to a word - ok as long as mbufs are word sized.
554  */
555 void
556 ne2000_readmem(nict, nich, asict, asich, src, dst, amount, useword)
557 	bus_space_tag_t nict;
558 	bus_space_handle_t nich;
559 	bus_space_tag_t asict;
560 	bus_space_handle_t asich;
561 	int src;
562 	u_int8_t *dst;
563 	size_t amount;
564 	int useword;
565 {
566 
567 	/* Select page 0 registers. */
568 	bus_space_write_1(nict, nich, ED_P0_CR,
569 	    ED_CR_RD2 | ED_CR_PAGE_0 | ED_CR_STA);
570 
571 	/* Round up to a word. */
572 	if (amount & 1)
573 		++amount;
574 
575 	/* Set up DMA byte count. */
576 	bus_space_write_1(nict, nich, ED_P0_RBCR0, amount);
577 	bus_space_write_1(nict, nich, ED_P0_RBCR1, amount >> 8);
578 
579 	/* Set up source address in NIC mem. */
580 	bus_space_write_1(nict, nich, ED_P0_RSAR0, src);
581 	bus_space_write_1(nict, nich, ED_P0_RSAR1, src >> 8);
582 
583 	bus_space_write_1(nict, nich, ED_P0_CR,
584 	    ED_CR_RD0 | ED_CR_PAGE_0 | ED_CR_STA);
585 
586 	if (useword)
587 		bus_space_read_multi_2(asict, asich, NE2000_ASIC_DATA,
588 		    (u_int16_t *)dst, amount >> 1);
589 	else
590 		bus_space_read_multi_1(asict, asich, NE2000_ASIC_DATA,
591 		    dst, amount);
592 }
593 
594 /*
595  * Stripped down routine for writing a linear buffer to NIC memory.  Only
596  * used in the probe routine to test the memory.  'len' must be even.
597  */
598 void
599 ne2000_writemem(nict, nich, asict, asich, src, dst, len, useword)
600 	bus_space_tag_t nict;
601 	bus_space_handle_t nich;
602 	bus_space_tag_t asict;
603 	bus_space_handle_t asich;
604 	u_int8_t *src;
605 	int dst;
606 	size_t len;
607 	int useword;
608 {
609 	int maxwait = 100;	/* about 120us */
610 
611 	/* Select page 0 registers. */
612 	bus_space_write_1(nict, nich, ED_P0_CR,
613 	    ED_CR_RD2 | ED_CR_PAGE_0 | ED_CR_STA);
614 
615 	/* Reset remote DMA complete flag. */
616 	bus_space_write_1(nict, nich, ED_P0_ISR, ED_ISR_RDC);
617 
618 	/* Set up DMA byte count. */
619 	bus_space_write_1(nict, nich, ED_P0_RBCR0, len);
620 	bus_space_write_1(nict, nich, ED_P0_RBCR1, len >> 8);
621 
622 	/* Set up destination address in NIC mem. */
623 	bus_space_write_1(nict, nich, ED_P0_RSAR0, dst);
624 	bus_space_write_1(nict, nich, ED_P0_RSAR1, dst >> 8);
625 
626 	/* Set remote DMA write. */
627 	bus_space_write_1(nict, nich, ED_P0_CR,
628 	    ED_CR_RD1 | ED_CR_PAGE_0 | ED_CR_STA);
629 
630 	if (useword)
631 		bus_space_write_multi_2(asict, asich, NE2000_ASIC_DATA,
632 		    (u_int16_t *)src, len >> 1);
633 	else
634 		bus_space_write_multi_1(asict, asich, NE2000_ASIC_DATA,
635 		    src, len);
636 
637 	/*
638 	 * Wait for remote DMA to complete.  This is necessary because on the
639 	 * transmit side, data is handled internally by the NIC in bursts, and
640 	 * we can't start another remote DMA until this one completes.  Not
641 	 * waiting causes really bad things to happen - like the NIC wedging
642 	 * the bus.
643 	 */
644 	while (((bus_space_read_1(nict, nich, ED_P0_ISR) & ED_ISR_RDC) !=
645 	    ED_ISR_RDC) && --maxwait);
646 
647 	if (maxwait == 0)
648 		printf("ne2000_writemem: failed to complete\n");
649 }
650