xref: /netbsd-src/sys/dev/ic/dm9000.c (revision c38e7cc395b1472a774ff828e46123de44c628e9)
1 /*	$NetBSD: dm9000.c,v 1.12 2017/07/29 01:31:20 riastradh Exp $	*/
2 
3 /*
4  * Copyright (c) 2009 Paul Fleischer
5  * All rights reserved.
6  *
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. The name of the company nor the name of the author may be used to
13  *    endorse or promote products derived from this software without specific
14  *    prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /* based on sys/dev/ic/cs89x0.c */
30 /*
31  * Copyright (c) 2004 Christopher Gilbert
32  * All rights reserved.
33  *
34  * 1. Redistributions of source code must retain the above copyright
35  *    notice, this list of conditions and the following disclaimer.
36  * 2. Redistributions in binary form must reproduce the above copyright
37  *    notice, this list of conditions and the following disclaimer in the
38  *    documentation and/or other materials provided with the distribution.
39  * 3. The name of the company nor the name of the author may be used to
40  *    endorse or promote products derived from this software without specific
41  *    prior written permission.
42  *
43  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
44  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
45  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
46  * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
47  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
48  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
49  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53  * SUCH DAMAGE.
54  */
55 
56 /*
57  * Copyright 1997
58  * Digital Equipment Corporation. All rights reserved.
59  *
60  * This software is furnished under license and may be used and
61  * copied only in accordance with the following terms and conditions.
62  * Subject to these conditions, you may download, copy, install,
63  * use, modify and distribute this software in source and/or binary
64  * form. No title or ownership is transferred hereby.
65  *
66  * 1) Any source code used, modified or distributed must reproduce
67  *    and retain this copyright notice and list of conditions as
68  *    they appear in the source file.
69  *
70  * 2) No right is granted to use any trade name, trademark, or logo of
71  *    Digital Equipment Corporation. Neither the "Digital Equipment
72  *    Corporation" name nor any trademark or logo of Digital Equipment
73  *    Corporation may be used to endorse or promote products derived
74  *    from this software without the prior written permission of
75  *    Digital Equipment Corporation.
76  *
77  * 3) This software is provided "AS-IS" and any express or implied
78  *    warranties, including but not limited to, any implied warranties
79  *    of merchantability, fitness for a particular purpose, or
80  *    non-infringement are disclaimed. In no event shall DIGITAL be
81  *    liable for any damages whatsoever, and in particular, DIGITAL
82  *    shall not be liable for special, indirect, consequential, or
83  *    incidental damages or damages for lost profits, loss of
84  *    revenue or loss of use, whether such damages arise in contract,
85  *    negligence, tort, under statute, in equity, at law or otherwise,
86  *    even if advised of the possibility of such damage.
87  */
88 
89 #include <sys/cdefs.h>
90 
91 #include <sys/param.h>
92 #include <sys/kernel.h>
93 #include <sys/systm.h>
94 #include <sys/mbuf.h>
95 #include <sys/syslog.h>
96 #include <sys/socket.h>
97 #include <sys/device.h>
98 #include <sys/malloc.h>
99 #include <sys/ioctl.h>
100 #include <sys/errno.h>
101 
102 #include <net/if.h>
103 #include <net/if_ether.h>
104 #include <net/if_media.h>
105 #ifdef INET
106 #include <netinet/in.h>
107 #include <netinet/if_inarp.h>
108 #endif
109 
110 #include <net/bpf.h>
111 #include <net/bpfdesc.h>
112 
113 #include <sys/bus.h>
114 #include <sys/intr.h>
115 
116 #include <dev/ic/dm9000var.h>
117 #include <dev/ic/dm9000reg.h>
118 
119 #if 1
120 #undef DM9000_DEBUG
121 #undef DM9000_TX_DEBUG
122 #undef DM9000_TX_DATA_DEBUG
123 #undef DM9000_RX_DEBUG
124 #undef  DM9000_RX_DATA_DEBUG
125 #else
126 #define DM9000_DEBUG
127 #define  DM9000_TX_DEBUG
128 #define DM9000_TX_DATA_DEBUG
129 #define DM9000_RX_DEBUG
130 #define  DM9000_RX_DATA_DEBUG
131 #endif
132 
133 #ifdef DM9000_DEBUG
134 #define DPRINTF(s) do {printf s; } while (/*CONSTCOND*/0)
135 #else
136 #define DPRINTF(s) do {} while (/*CONSTCOND*/0)
137 #endif
138 
139 #ifdef DM9000_TX_DEBUG
140 #define TX_DPRINTF(s) do {printf s; } while (/*CONSTCOND*/0)
141 #else
142 #define TX_DPRINTF(s) do {} while (/*CONSTCOND*/0)
143 #endif
144 
145 #ifdef DM9000_RX_DEBUG
146 #define RX_DPRINTF(s) do {printf s; } while (/*CONSTCOND*/0)
147 #else
148 #define RX_DPRINTF(s) do {} while (/*CONSTCOND*/0)
149 #endif
150 
151 #ifdef DM9000_RX_DATA_DEBUG
152 #define RX_DATA_DPRINTF(s) do {printf s; } while (/*CONSTCOND*/0)
153 #else
154 #define RX_DATA_DPRINTF(s) do {} while (/*CONSTCOND*/0)
155 #endif
156 
157 #ifdef DM9000_TX_DATA_DEBUG
158 #define TX_DATA_DPRINTF(s) do {printf s; } while (/*CONSTCOND*/0)
159 #else
160 #define TX_DATA_DPRINTF(s) do {} while (/*CONSTCOND*/0)
161 #endif
162 
163 /*** Internal PHY functions ***/
164 uint16_t dme_phy_read(struct dme_softc *, int );
165 void	dme_phy_write(struct dme_softc *, int, uint16_t);
166 void	dme_phy_init(struct dme_softc *);
167 void	dme_phy_reset(struct dme_softc *);
168 void	dme_phy_update_media(struct dme_softc *);
169 void	dme_phy_check_link(void *);
170 
171 /*** Methods registered in struct ifnet ***/
172 void	dme_start_output(struct ifnet *);
173 int	dme_init(struct ifnet *);
174 int	dme_ioctl(struct ifnet *, u_long, void *);
175 void	dme_stop(struct ifnet *, int);
176 
177 int	dme_mediachange(struct ifnet *);
178 void	dme_mediastatus(struct ifnet *, struct ifmediareq *);
179 
180 /*** Internal methods ***/
181 
182 /* Prepare data to be transmitted (i.e. dequeue and load it into the DM9000) */
183 void    dme_prepare(struct dme_softc *, struct ifnet *);
184 
185 /* Transmit prepared data */
186 void    dme_transmit(struct dme_softc *);
187 
188 /* Receive data */
189 void    dme_receive(struct dme_softc *, struct ifnet *);
190 
191 /* Software Initialize/Reset of the DM9000 */
192 void    dme_reset(struct dme_softc *);
193 
194 /* Configure multicast filter */
195 void	dme_set_addr_filter(struct dme_softc *);
196 
197 /* Set media */
198 int	dme_set_media(struct dme_softc *, int );
199 
200 /* Read/write packet data from/to DM9000 IC in various transfer sizes */
201 int	dme_pkt_read_2(struct dme_softc *, struct ifnet *, struct mbuf **);
202 int	dme_pkt_write_2(struct dme_softc *, struct mbuf *);
203 int	dme_pkt_read_1(struct dme_softc *, struct ifnet *, struct mbuf **);
204 int	dme_pkt_write_1(struct dme_softc *, struct mbuf *);
205 /* TODO: Implement 32 bit read/write functions */
206 
207 uint16_t
208 dme_phy_read(struct dme_softc *sc, int reg)
209 {
210 	uint16_t val;
211 	/* Select Register to read*/
212 	dme_write(sc, DM9000_EPAR, DM9000_EPAR_INT_PHY +
213 	    (reg & DM9000_EPAR_EROA_MASK));
214 	/* Select read operation (DM9000_EPCR_ERPRR) from the PHY */
215 	dme_write(sc, DM9000_EPCR, DM9000_EPCR_ERPRR + DM9000_EPCR_EPOS_PHY);
216 
217 	/* Wait until access to PHY has completed */
218 	while (dme_read(sc, DM9000_EPCR) & DM9000_EPCR_ERRE);
219 
220 	/* Reset ERPRR-bit */
221 	dme_write(sc, DM9000_EPCR, DM9000_EPCR_EPOS_PHY);
222 
223 	val = dme_read(sc, DM9000_EPDRL);
224 	val += dme_read(sc, DM9000_EPDRH) << 8;
225 
226 	return val;
227 }
228 
229 void
230 dme_phy_write(struct dme_softc *sc, int reg, uint16_t value)
231 {
232 	/* Select Register to write*/
233 	dme_write(sc, DM9000_EPAR, DM9000_EPAR_INT_PHY +
234 	    (reg & DM9000_EPAR_EROA_MASK));
235 
236 	/* Write data to the two data registers */
237 	dme_write(sc, DM9000_EPDRL, value & 0xFF);
238 	dme_write(sc, DM9000_EPDRH, (value >> 8) & 0xFF);
239 
240 	/* Select write operation (DM9000_EPCR_ERPRW) from the PHY */
241 	dme_write(sc, DM9000_EPCR, DM9000_EPCR_ERPRW + DM9000_EPCR_EPOS_PHY);
242 
243 	/* Wait until access to PHY has completed */
244 	while(dme_read(sc, DM9000_EPCR) & DM9000_EPCR_ERRE);
245 
246 	/* Reset ERPRR-bit */
247 	dme_write(sc, DM9000_EPCR, DM9000_EPCR_EPOS_PHY);
248 }
249 
250 void
251 dme_phy_init(struct dme_softc *sc)
252 {
253 	u_int ifm_media = sc->sc_media.ifm_media;
254 	uint32_t bmcr, anar;
255 
256 	bmcr = dme_phy_read(sc, DM9000_PHY_BMCR);
257 	anar = dme_phy_read(sc, DM9000_PHY_ANAR);
258 
259 	anar = anar & ~DM9000_PHY_ANAR_10_HDX
260 		& ~DM9000_PHY_ANAR_10_FDX
261 		& ~DM9000_PHY_ANAR_TX_HDX
262 		& ~DM9000_PHY_ANAR_TX_FDX;
263 
264 	switch (IFM_SUBTYPE(ifm_media)) {
265 	case IFM_AUTO:
266 		bmcr |= DM9000_PHY_BMCR_AUTO_NEG_EN;
267 		anar |= DM9000_PHY_ANAR_10_HDX |
268 			DM9000_PHY_ANAR_10_FDX |
269 			DM9000_PHY_ANAR_TX_HDX |
270 			DM9000_PHY_ANAR_TX_FDX;
271 		break;
272 	case IFM_10_T:
273 		//bmcr &= ~DM9000_PHY_BMCR_AUTO_NEG_EN;
274 		bmcr &= ~DM9000_PHY_BMCR_SPEED_SELECT;
275 		if (ifm_media & IFM_FDX)
276 			anar |= DM9000_PHY_ANAR_10_FDX;
277 		else
278 			anar |= DM9000_PHY_ANAR_10_HDX;
279 		break;
280 	case IFM_100_TX:
281 		//bmcr &= ~DM9000_PHY_BMCR_AUTO_NEG_EN;
282 		bmcr |= DM9000_PHY_BMCR_SPEED_SELECT;
283 		if (ifm_media & IFM_FDX)
284 			anar |= DM9000_PHY_ANAR_TX_FDX;
285 		else
286 			anar |= DM9000_PHY_ANAR_TX_HDX;
287 
288 		break;
289 	}
290 
291 	if(ifm_media & IFM_FDX) {
292 		bmcr |= DM9000_PHY_BMCR_DUPLEX_MODE;
293 	} else {
294 		bmcr &= ~DM9000_PHY_BMCR_DUPLEX_MODE;
295 	}
296 
297 	dme_phy_write(sc, DM9000_PHY_BMCR, bmcr);
298 	dme_phy_write(sc, DM9000_PHY_ANAR, anar);
299 }
300 
301 void
302 dme_phy_reset(struct dme_softc *sc)
303 {
304 	uint32_t reg;
305 
306 	/* PHY Reset */
307 	dme_phy_write(sc, DM9000_PHY_BMCR, DM9000_PHY_BMCR_RESET);
308 
309 	reg = dme_read(sc, DM9000_GPCR);
310 	dme_write(sc, DM9000_GPCR, reg & ~DM9000_GPCR_GPIO0_OUT);
311 	reg = dme_read(sc, DM9000_GPR);
312 	dme_write(sc, DM9000_GPR, reg | DM9000_GPR_PHY_PWROFF);
313 
314 	dme_phy_init(sc);
315 
316 	reg = dme_read(sc, DM9000_GPR);
317 	dme_write(sc, DM9000_GPR, reg & ~DM9000_GPR_PHY_PWROFF);
318 	reg = dme_read(sc, DM9000_GPCR);
319 	dme_write(sc, DM9000_GPCR, reg | DM9000_GPCR_GPIO0_OUT);
320 
321 	dme_phy_update_media(sc);
322 }
323 
324 void
325 dme_phy_update_media(struct dme_softc *sc)
326 {
327 	u_int ifm_media = sc->sc_media.ifm_media;
328 	uint32_t reg;
329 
330 	if (IFM_SUBTYPE(ifm_media) == IFM_AUTO) {
331 		/* If auto-negotiation is used, ensures that it is completed
332 		 before trying to extract any media information. */
333 		reg = dme_phy_read(sc, DM9000_PHY_BMSR);
334 		if ((reg & DM9000_PHY_BMSR_AUTO_NEG_AB) == 0) {
335 			/* Auto-negotation not possible, therefore there is no
336 			   reason to try obtain any media information. */
337 			return;
338 		}
339 
340 		/* Then loop until the negotiation is completed. */
341 		while ((reg & DM9000_PHY_BMSR_AUTO_NEG_COM) == 0) {
342 			/* TODO: Bail out after a finite number of attempts
343 			 in case something goes wrong. */
344 			preempt();
345 			reg = dme_phy_read(sc, DM9000_PHY_BMSR);
346 		}
347 	}
348 
349 
350 	sc->sc_media_active = IFM_ETHER;
351 	reg = dme_phy_read(sc, DM9000_PHY_BMCR);
352 
353 	if (reg & DM9000_PHY_BMCR_SPEED_SELECT) {
354 		sc->sc_media_active |= IFM_100_TX;
355 	} else {
356 		sc->sc_media_active |= IFM_10_T;
357 	}
358 
359 	if (reg & DM9000_PHY_BMCR_DUPLEX_MODE) {
360 		sc->sc_media_active |= IFM_FDX;
361 	}
362 }
363 
364 void
365 dme_phy_check_link(void *arg)
366 {
367 	struct dme_softc *sc = arg;
368 	uint32_t reg;
369 	int s;
370 
371 	s = splnet();
372 
373 	reg = dme_read(sc, DM9000_NSR) & DM9000_NSR_LINKST;
374 
375 	if( reg )
376 		reg = IFM_ETHER | IFM_AVALID | IFM_ACTIVE;
377 	else {
378 		reg = IFM_ETHER | IFM_AVALID;
379 		sc->sc_media_active = IFM_NONE;
380 	}
381 
382 	if ( (sc->sc_media_status != reg) && (reg & IFM_ACTIVE)) {
383 		dme_phy_reset(sc);
384 	}
385 
386 	sc->sc_media_status = reg;
387 
388 	callout_schedule(&sc->sc_link_callout, mstohz(2000));
389 	splx(s);
390 }
391 
392 int
393 dme_set_media(struct dme_softc *sc, int media)
394 {
395 	int s;
396 
397 	s = splnet();
398 	sc->sc_media.ifm_media = media;
399 	dme_phy_reset(sc);
400 
401 	splx(s);
402 
403 	return 0;
404 }
405 
406 int
407 dme_attach(struct dme_softc *sc, const uint8_t *enaddr)
408 {
409 	struct ifnet	*ifp = &sc->sc_ethercom.ec_if;
410 	uint8_t		b[2];
411 	uint16_t	io_mode;
412 
413 	dme_read_c(sc, DM9000_VID0, b, 2);
414 #if BYTE_ORDER == BIG_ENDIAN
415 	sc->sc_vendor_id = (b[0] << 8) | b[1];
416 #else
417 	sc->sc_vendor_id = b[0] | (b[1] << 8);
418 #endif
419 	dme_read_c(sc, DM9000_PID0, b, 2);
420 #if BYTE_ORDER == BIG_ENDIAN
421 	sc->sc_product_id = (b[0] << 8) | b[1];
422 #else
423 	sc->sc_product_id = b[0] | (b[1] << 8);
424 #endif
425 	/* TODO: Check the vendor ID as well */
426 	if (sc->sc_product_id != 0x9000) {
427 		panic("dme_attach: product id mismatch (0x%hx != 0x9000)",
428 		    sc->sc_product_id);
429 	}
430 
431 	/* Initialize ifnet structure. */
432 	strlcpy(ifp->if_xname, device_xname(sc->sc_dev), IFNAMSIZ);
433 	ifp->if_softc = sc;
434 	ifp->if_start = dme_start_output;
435 	ifp->if_init = dme_init;
436 	ifp->if_ioctl = dme_ioctl;
437 	ifp->if_stop = dme_stop;
438 	ifp->if_watchdog = NULL;	/* no watchdog at this stage */
439 	ifp->if_flags = IFF_SIMPLEX | IFF_NOTRAILERS | IFF_BROADCAST |
440 			IFF_MULTICAST;
441 	IFQ_SET_READY(&ifp->if_snd);
442 
443 	/* Initialize ifmedia structures. */
444 	ifmedia_init(&sc->sc_media, 0, dme_mediachange, dme_mediastatus);
445 	ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_AUTO, 0, NULL);
446 	ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_10_T|IFM_FDX, 0, NULL);
447 	ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_10_T, 0, NULL);
448 	ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_100_TX|IFM_FDX, 0, NULL);
449 	ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_100_TX, 0, NULL);
450 
451 	ifmedia_set(&sc->sc_media, IFM_ETHER|IFM_AUTO);
452 
453 	if (enaddr != NULL)
454 		memcpy(sc->sc_enaddr, enaddr, sizeof(sc->sc_enaddr));
455 	/* TODO: Support an EEPROM attached to the DM9000 chip */
456 
457 	callout_init(&sc->sc_link_callout, 0);
458 	callout_setfunc(&sc->sc_link_callout, dme_phy_check_link, sc);
459 
460 	sc->sc_media_status = 0;
461 
462 	/* Configure DM9000 with the MAC address */
463 	dme_write_c(sc, DM9000_PAB0, sc->sc_enaddr, 6);
464 
465 #ifdef DM9000_DEBUG
466 	{
467 		uint8_t macAddr[6];
468 		dme_read_c(sc, DM9000_PAB0, macAddr, 6);
469 		printf("DM9000 configured with MAC address: ");
470 		for (int i = 0; i < 6; i++) {
471 			printf("%02X:", macAddr[i]);
472 		}
473 		printf("\n");
474 	}
475 #endif
476 
477 	if_attach(ifp);
478 	ether_ifattach(ifp, sc->sc_enaddr);
479 
480 #ifdef DM9000_DEBUG
481 	{
482 		uint8_t network_state;
483 		network_state = dme_read(sc, DM9000_NSR);
484 		printf("DM9000 Link status: ");
485 		if (network_state & DM9000_NSR_LINKST) {
486 			if (network_state & DM9000_NSR_SPEED)
487 				printf("10Mbps");
488 			else
489 				printf("100Mbps");
490 		} else {
491 			printf("Down");
492 		}
493 		printf("\n");
494 	}
495 #endif
496 
497 	io_mode = (dme_read(sc, DM9000_ISR) &
498 	    DM9000_IOMODE_MASK) >> DM9000_IOMODE_SHIFT;
499 
500 	DPRINTF(("DM9000 Operation Mode: "));
501 	switch( io_mode) {
502 	case DM9000_MODE_16BIT:
503 		DPRINTF(("16-bit mode"));
504 		sc->sc_data_width = 2;
505 		sc->sc_pkt_write = dme_pkt_write_2;
506 		sc->sc_pkt_read = dme_pkt_read_2;
507 		break;
508 	case DM9000_MODE_32BIT:
509 		DPRINTF(("32-bit mode"));
510 		sc->sc_data_width = 4;
511 		panic("32bit mode is unsupported\n");
512 		break;
513 	case DM9000_MODE_8BIT:
514 		DPRINTF(("8-bit mode"));
515 		sc->sc_data_width = 1;
516 		sc->sc_pkt_write = dme_pkt_write_1;
517 		sc->sc_pkt_read = dme_pkt_read_1;
518 		break;
519 	default:
520 		DPRINTF(("Invalid mode"));
521 		break;
522 	}
523 	DPRINTF(("\n"));
524 
525 	callout_schedule(&sc->sc_link_callout, mstohz(2000));
526 
527 	return 0;
528 }
529 
530 int dme_intr(void *arg)
531 {
532 	struct dme_softc *sc = arg;
533 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
534 	uint8_t status;
535 
536 
537 	DPRINTF(("dme_intr: Begin\n"));
538 
539 	/* Disable interrupts */
540 	dme_write(sc, DM9000_IMR, DM9000_IMR_PAR );
541 
542 	status = dme_read(sc, DM9000_ISR);
543 	dme_write(sc, DM9000_ISR, status);
544 
545 	if (status & DM9000_ISR_PRS) {
546 		if (ifp->if_flags & IFF_RUNNING )
547 			dme_receive(sc, ifp);
548 	}
549 	if (status & DM9000_ISR_PTS) {
550 		uint8_t nsr;
551 		uint8_t tx_status = 0x01; /* Initialize to an error value */
552 
553 		/* A packet has been transmitted */
554 		sc->txbusy = 0;
555 
556 		nsr = dme_read(sc, DM9000_NSR);
557 
558 		if (nsr & DM9000_NSR_TX1END) {
559 			tx_status = dme_read(sc, DM9000_TSR1);
560 			TX_DPRINTF(("dme_intr: Sent using channel 0\n"));
561 		} else if (nsr & DM9000_NSR_TX2END) {
562 			tx_status = dme_read(sc, DM9000_TSR2);
563 			TX_DPRINTF(("dme_intr: Sent using channel 1\n"));
564 		}
565 
566 		if (tx_status == 0x0) {
567 			/* Frame successfully sent */
568 			ifp->if_opackets++;
569 		} else {
570 			ifp->if_oerrors++;
571 		}
572 
573 		/* If we have nothing ready to transmit, prepare something */
574 		if (!sc->txready) {
575 			dme_prepare(sc, ifp);
576 		}
577 
578 		if (sc->txready)
579 			dme_transmit(sc);
580 
581 		/* Prepare the next frame */
582 		dme_prepare(sc, ifp);
583 
584 	}
585 #ifdef notyet
586 	if (status & DM9000_ISR_LNKCHNG) {
587 	}
588 #endif
589 
590 	/* Enable interrupts again */
591 	dme_write(sc, DM9000_IMR, DM9000_IMR_PAR | DM9000_IMR_PRM |
592 		 DM9000_IMR_PTM);
593 
594 	DPRINTF(("dme_intr: End\n"));
595 
596 	return 1;
597 }
598 
599 void
600 dme_start_output(struct ifnet *ifp)
601 {
602 	struct dme_softc *sc;
603 
604 	sc = ifp->if_softc;
605 
606 	DPRINTF(("dme_start_output: Begin\n"));
607 
608 	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING) {
609 		printf("No output\n");
610 		return;
611 	}
612 
613 	if (sc->txbusy && sc->txready) {
614 		panic("DM9000: Internal error, trying to send without"
615 		    " any empty queue\n");
616 	}
617 
618 	dme_prepare(sc, ifp);
619 
620 	if (sc->txbusy == 0) {
621 		/* We are ready to transmit right away */
622 		dme_transmit(sc);
623 		dme_prepare(sc, ifp); /* Prepare next one */
624 	} else {
625 		/* We need to wait until the current packet has
626 		 * been transmitted.
627 		 */
628 		ifp->if_flags |= IFF_OACTIVE;
629 	}
630 
631 	DPRINTF(("dme_start_output: End\n"));
632 }
633 
634 void
635 dme_prepare(struct dme_softc *sc, struct ifnet *ifp)
636 {
637 	struct mbuf *bufChain;
638 	uint16_t length;
639 
640 	TX_DPRINTF(("dme_prepare: Entering\n"));
641 
642 	if (sc->txready)
643 		panic("dme_prepare: Someone called us with txready set\n");
644 
645 	IFQ_DEQUEUE(&ifp->if_snd, bufChain);
646 	if (bufChain == NULL) {
647 		TX_DPRINTF(("dme_prepare: Nothing to transmit\n"));
648 		ifp->if_flags &= ~IFF_OACTIVE; /* Clear OACTIVE bit */
649 		return; /* Nothing to transmit */
650 	}
651 
652 	/* Element has now been removed from the queue, so we better send it */
653 
654 	if (ifp->if_bpf)
655 		bpf_mtap(ifp, bufChain);
656 
657 	/* Setup the DM9000 to accept the writes, and then write each buf in
658 	   the chain. */
659 
660 	TX_DATA_DPRINTF(("dme_prepare: Writing data: "));
661 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, sc->dme_io, DM9000_MWCMD);
662 	length = sc->sc_pkt_write(sc, bufChain);
663 	TX_DATA_DPRINTF(("\n"));
664 
665 	if (length % sc->sc_data_width != 0) {
666 		panic("dme_prepare: length is not compatible with IO_MODE");
667 	}
668 
669 	sc->txready_length = length;
670 	sc->txready = 1;
671 
672 	TX_DPRINTF(("dme_prepare: txbusy: %d\ndme_prepare: "
673 		"txready: %d, txready_length: %d\n",
674 		sc->txbusy, sc->txready, sc->txready_length));
675 
676 	m_freem(bufChain);
677 
678 	TX_DPRINTF(("dme_prepare: Leaving\n"));
679 }
680 
681 int
682 dme_init(struct ifnet *ifp)
683 {
684 	int s;
685 	struct dme_softc *sc = ifp->if_softc;
686 
687 	dme_stop(ifp, 0);
688 
689 	s = splnet();
690 
691 	dme_reset(sc);
692 
693 	sc->sc_ethercom.ec_if.if_flags |= IFF_RUNNING;
694 	sc->sc_ethercom.ec_if.if_flags &= ~IFF_OACTIVE;
695 	sc->sc_ethercom.ec_if.if_timer = 0;
696 
697 	splx(s);
698 
699 	return 0;
700 }
701 
702 int
703 dme_ioctl(struct ifnet *ifp, u_long cmd, void *data)
704 {
705 	struct dme_softc *sc = ifp->if_softc;
706 	struct ifreq *ifr = data;
707 	int s, error = 0;
708 
709 	s = splnet();
710 
711 	switch(cmd) {
712 	case SIOCGIFMEDIA:
713 	case SIOCSIFMEDIA:
714 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd);
715 		break;
716 	default:
717 		error = ether_ioctl(ifp, cmd, data);
718 		if (error == ENETRESET) {
719 			if (ifp->if_flags && IFF_RUNNING) {
720 				/* Address list has changed, reconfigure
721 				   filter */
722 				dme_set_addr_filter(sc);
723 			}
724 			error = 0;
725 		}
726 		break;
727 	}
728 
729 	splx(s);
730 	return error;
731 }
732 
733 void
734 dme_stop(struct ifnet *ifp, int disable)
735 {
736 	struct dme_softc *sc = ifp->if_softc;
737 
738 	/* Not quite sure what to do when called with disable == 0 */
739 	if (disable) {
740 		/* Disable RX */
741 		dme_write(sc, DM9000_RCR, 0x0);
742 	}
743 
744 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
745 	ifp->if_timer = 0;
746 }
747 
748 int
749 dme_mediachange(struct ifnet *ifp)
750 {
751 	struct dme_softc *sc = ifp->if_softc;
752 
753 	return dme_set_media(sc, sc->sc_media.ifm_cur->ifm_media);
754 }
755 
756 void
757 dme_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
758 {
759 	struct dme_softc *sc = ifp->if_softc;
760 
761 	ifmr->ifm_active = sc->sc_media_active;
762 	ifmr->ifm_status = sc->sc_media_status;
763 }
764 
765 void
766 dme_transmit(struct dme_softc *sc)
767 {
768 
769 	TX_DPRINTF(("dme_transmit: PRE: txready: %d, txbusy: %d\n",
770 		sc->txready, sc->txbusy));
771 
772 	dme_write(sc, DM9000_TXPLL, sc->txready_length & 0xff);
773 	dme_write(sc, DM9000_TXPLH, (sc->txready_length >> 8) & 0xff );
774 
775 	/* Request to send the packet */
776 	dme_read(sc, DM9000_ISR);
777 
778 	dme_write(sc, DM9000_TCR, DM9000_TCR_TXREQ);
779 
780 	sc->txready = 0;
781 	sc->txbusy = 1;
782 	sc->txready_length = 0;
783 }
784 
785 void
786 dme_receive(struct dme_softc *sc, struct ifnet *ifp)
787 {
788 	uint8_t ready = 0x01;
789 
790 	DPRINTF(("inside dme_receive\n"));
791 
792 	while (ready == 0x01) {
793 		/* Packet received, retrieve it */
794 
795 		/* Read without address increment to get the ready byte without
796 		   moving past it. */
797 		bus_space_write_1(sc->sc_iot, sc->sc_ioh,
798 		    sc->dme_io, DM9000_MRCMDX);
799 		/* Dummy ready */
800 		ready = bus_space_read_1(sc->sc_iot, sc->sc_ioh, sc->dme_data);
801 		ready = bus_space_read_1(sc->sc_iot, sc->sc_ioh, sc->dme_data);
802 		ready &= 0x03;	/* we only want bits 1:0 */
803 		if (ready == 0x01) {
804 			uint8_t		rx_status;
805 			struct mbuf	*m;
806 
807 			/* Read with address increment. */
808 			bus_space_write_1(sc->sc_iot, sc->sc_ioh,
809 					  sc->dme_io, DM9000_MRCMD);
810 
811 			rx_status = sc->sc_pkt_read(sc, ifp, &m);
812 			if (m == NULL) {
813 				/* failed to allocate a receive buffer */
814 				ifp->if_ierrors++;
815 				RX_DPRINTF(("dme_receive: "
816 					"Error allocating buffer\n"));
817 			} else if (rx_status & (DM9000_RSR_CE | DM9000_RSR_PLE)) {
818 				/* Error while receiving the packet,
819 				 * discard it and keep track of counters
820 				 */
821 				ifp->if_ierrors++;
822 				RX_DPRINTF(("dme_receive: "
823 					"Error reciving packet\n"));
824 			} else if (rx_status & DM9000_RSR_LCS) {
825 				ifp->if_collisions++;
826 			} else {
827 				if_percpuq_enqueue(ifp->if_percpuq, m);
828 			}
829 
830 		} else if (ready != 0x00) {
831 			/* Should this be logged somehow? */
832 			printf("%s: Resetting chip\n",
833 			       device_xname(sc->sc_dev));
834 			dme_reset(sc);
835 		}
836 	}
837 }
838 
839 void
840 dme_reset(struct dme_softc *sc)
841 {
842 	uint8_t var;
843 
844 	/* We only re-initialized the PHY in this function the first time it is
845 	   called. */
846 	if( !sc->sc_phy_initialized) {
847 		/* PHY Reset */
848 		dme_phy_write(sc, DM9000_PHY_BMCR, DM9000_PHY_BMCR_RESET);
849 
850 		/* PHY Power Down */
851 		var = dme_read(sc, DM9000_GPR);
852 		dme_write(sc, DM9000_GPR, var | DM9000_GPR_PHY_PWROFF);
853 	}
854 
855 	/* Reset the DM9000 twice, as described in section 2 of the Programming
856 	   Guide.
857 	   The PHY is initialized and enabled between those two resets.
858 	 */
859 
860 	/* Software Reset*/
861 	dme_write(sc, DM9000_NCR,
862 	    DM9000_NCR_RST | DM9000_NCR_LBK_MAC_INTERNAL);
863 	delay(20);
864 	dme_write(sc, DM9000_NCR, 0x0);
865 
866 	if( !sc->sc_phy_initialized) {
867 		/* PHY Initialization */
868 		dme_phy_init(sc);
869 
870 		/* PHY Enable */
871 		var = dme_read(sc, DM9000_GPR);
872 		dme_write(sc, DM9000_GPR, var & ~DM9000_GPR_PHY_PWROFF);
873 		var = dme_read(sc, DM9000_GPCR);
874 		dme_write(sc, DM9000_GPCR, var | DM9000_GPCR_GPIO0_OUT);
875 
876 		dme_write(sc, DM9000_NCR,
877 			  DM9000_NCR_RST | DM9000_NCR_LBK_MAC_INTERNAL);
878 		delay(20);
879 		dme_write(sc, DM9000_NCR, 0x0);
880 	}
881 
882 	/* Select internal PHY, no wakeup event, no collosion mode,
883 	 * normal loopback mode.
884 	 */
885 	dme_write(sc, DM9000_NCR, DM9000_NCR_LBK_NORMAL );
886 
887 	/* Will clear TX1END, TX2END, and WAKEST fields by reading DM9000_NSR*/
888 	dme_read(sc, DM9000_NSR);
889 
890 	/* Enable wraparound of read/write pointer, packet received latch,
891 	 * and packet transmitted latch.
892 	 */
893 	dme_write(sc, DM9000_IMR,
894 	    DM9000_IMR_PAR | DM9000_IMR_PRM | DM9000_IMR_PTM);
895 
896 	/* Setup multicast address filter, and enable RX. */
897 	dme_set_addr_filter(sc);
898 
899 	/* Obtain media information from PHY */
900 	dme_phy_update_media(sc);
901 
902 	sc->txbusy = 0;
903 	sc->txready = 0;
904 	sc->sc_phy_initialized = 1;
905 }
906 
907 void
908 dme_set_addr_filter(struct dme_softc *sc)
909 {
910 	struct ether_multi	*enm;
911 	struct ether_multistep	step;
912 	struct ethercom		*ec;
913 	struct ifnet		*ifp;
914 	uint16_t		af[4];
915 	int			i;
916 
917 	ec = &sc->sc_ethercom;
918 	ifp = &ec->ec_if;
919 
920 	if (ifp->if_flags & IFF_PROMISC) {
921 		dme_write(sc, DM9000_RCR, DM9000_RCR_RXEN  |
922 					  DM9000_RCR_WTDIS |
923 					  DM9000_RCR_PRMSC);
924 		ifp->if_flags |= IFF_ALLMULTI;
925 		return;
926 	}
927 
928 	af[0] = af[1] = af[2] = af[3] = 0x0000;
929 	ifp->if_flags &= ~IFF_ALLMULTI;
930 
931 	ETHER_FIRST_MULTI(step, ec, enm);
932 	while (enm != NULL) {
933 		uint16_t hash;
934 		if (memcpy(enm->enm_addrlo, enm->enm_addrhi,
935 		    sizeof(enm->enm_addrlo))) {
936 			/*
937 	                 * We must listen to a range of multicast addresses.
938 	                 * For now, just accept all multicasts, rather than
939 	                 * trying to set only those filter bits needed to match
940 	                 * the range.  (At this time, the only use of address
941 	                 * ranges is for IP multicast routing, for which the
942 	                 * range is big enough to require all bits set.)
943 	                 */
944 			ifp->if_flags |= IFF_ALLMULTI;
945 			af[0] = af[1] = af[2] = af[3] = 0xffff;
946 			break;
947 		} else {
948 			hash = ether_crc32_le(enm->enm_addrlo, ETHER_ADDR_LEN) & 0x3F;
949 			af[(uint16_t)(hash>>4)] |= (uint16_t)(1 << (hash % 16));
950 			ETHER_NEXT_MULTI(step, enm);
951 		}
952 	}
953 
954 	/* Write the multicast address filter */
955 	for(i=0; i<4; i++) {
956 		dme_write(sc, DM9000_MAB0+i*2, af[i] & 0xFF);
957 		dme_write(sc, DM9000_MAB0+i*2+1, (af[i] >> 8) & 0xFF);
958 	}
959 
960 	/* Setup RX controls */
961 	dme_write(sc, DM9000_RCR, DM9000_RCR_RXEN | DM9000_RCR_WTDIS);
962 }
963 
964 int
965 dme_pkt_write_2(struct dme_softc *sc, struct mbuf *bufChain)
966 {
967 	int left_over_count = 0; /* Number of bytes from previous mbuf, which
968 				    need to be written with the next.*/
969 	uint16_t left_over_buf = 0;
970 	int length = 0;
971 	struct mbuf *buf;
972 	uint8_t *write_ptr;
973 
974 	/* We expect that the DM9000 has been setup to accept writes before
975 	   this function is called. */
976 
977 	for (buf = bufChain; buf != NULL; buf = buf->m_next) {
978 		int to_write = buf->m_len;
979 
980 		length += to_write;
981 
982 		write_ptr = buf->m_data;
983 		while (to_write > 0 ||
984 		       (buf->m_next == NULL && left_over_count > 0)
985 		       ) {
986 			if (left_over_count > 0) {
987 				uint8_t b = 0;
988 				DPRINTF(("dme_pkt_write_16: "
989 					 "Writing left over byte\n"));
990 
991 				if (to_write > 0) {
992 					b = *write_ptr;
993 					to_write--;
994 					write_ptr++;
995 
996 					DPRINTF(("Took single byte\n"));
997 				} else {
998 					DPRINTF(("Leftover in last run\n"));
999 					length++;
1000 				}
1001 
1002 				/* Does shift direction depend on endianess? */
1003 				left_over_buf = left_over_buf | (b << 8);
1004 
1005 				bus_space_write_2(sc->sc_iot, sc->sc_ioh,
1006 						  sc->dme_data, left_over_buf);
1007 				TX_DATA_DPRINTF(("%02X ", left_over_buf));
1008 				left_over_count = 0;
1009 			} else if ((long)write_ptr % 2 != 0) {
1010 				/* Misaligned data */
1011 				DPRINTF(("dme_pkt_write_16: "
1012 					 "Detected misaligned data\n"));
1013 				left_over_buf = *write_ptr;
1014 				left_over_count = 1;
1015 				write_ptr++;
1016 				to_write--;
1017 			} else {
1018 				int i;
1019 				uint16_t *dptr = (uint16_t *)write_ptr;
1020 
1021 				/* A block of aligned data. */
1022 				for(i = 0; i < to_write / 2; i++) {
1023 					/* buf will be half-word aligned
1024 					 * all the time
1025 					 */
1026 					bus_space_write_2(sc->sc_iot,
1027 					    sc->sc_ioh, sc->dme_data, *dptr);
1028 					TX_DATA_DPRINTF(("%02X %02X ",
1029 					    *dptr & 0xFF, (*dptr >> 8) & 0xFF));
1030 					dptr++;
1031 				}
1032 
1033 				write_ptr += i * 2;
1034 				if (to_write % 2 != 0) {
1035 					DPRINTF(("dme_pkt_write_16: "
1036 						 "to_write %% 2: %d\n",
1037 						 to_write % 2));
1038 					left_over_count = 1;
1039 					/* XXX: Does this depend on
1040 					 * the endianess?
1041 					 */
1042 					left_over_buf = *write_ptr;
1043 
1044 					write_ptr++;
1045 					to_write--;
1046 					DPRINTF(("dme_pkt_write_16: "
1047 						 "to_write (after): %d\n",
1048 						 to_write));
1049 					DPRINTF(("dme_pkt_write_16: i * 2: %d\n",
1050 						 i*2));
1051 				}
1052 				to_write -= i * 2;
1053 			}
1054 		} /* while(...) */
1055 	} /* for(...) */
1056 
1057 	return length;
1058 }
1059 
1060 int
1061 dme_pkt_read_2(struct dme_softc *sc, struct ifnet *ifp, struct mbuf **outBuf)
1062 {
1063 	uint8_t rx_status;
1064 	struct mbuf *m;
1065 	uint16_t data;
1066 	uint16_t frame_length;
1067 	uint16_t i;
1068 	uint16_t *buf;
1069 
1070 	data = bus_space_read_2(sc->sc_iot, sc->sc_ioh, sc->dme_data);
1071 
1072 	rx_status = data & 0xFF;
1073 	frame_length = bus_space_read_2(sc->sc_iot,
1074 					sc->sc_ioh, sc->dme_data);
1075 	if (frame_length > ETHER_MAX_LEN) {
1076 		printf("Got frame of length: %d\n", frame_length);
1077 		printf("ETHER_MAX_LEN is: %d\n", ETHER_MAX_LEN);
1078 		panic("Something is rotten");
1079 	}
1080 	RX_DPRINTF(("dme_receive: "
1081 		    "rx_statux: 0x%x, frame_length: %d\n",
1082 		    rx_status, frame_length));
1083 
1084 
1085 	m = dme_alloc_receive_buffer(ifp, frame_length);
1086 	if (m == NULL) {
1087 		/*
1088 		 * didn't get a receive buffer, so we read the rest of the
1089 		 * packet, throw it away and return an error
1090 		 */
1091 		for (i = 0; i < frame_length; i += 2 ) {
1092 			data = bus_space_read_2(sc->sc_iot,
1093 					sc->sc_ioh, sc->dme_data);
1094 		}
1095 		*outBuf = NULL;
1096 		return 0;
1097 	}
1098 
1099 	buf = mtod(m, uint16_t*);
1100 
1101 	RX_DPRINTF(("dme_receive: "));
1102 
1103 	for (i = 0; i < frame_length; i += 2 ) {
1104 		data = bus_space_read_2(sc->sc_iot,
1105 					sc->sc_ioh, sc->dme_data);
1106 		if ( (frame_length % 2 != 0) &&
1107 		     (i == frame_length - 1) ) {
1108 			data = data & 0xff;
1109 			RX_DPRINTF((" L "));
1110 		}
1111 		*buf = data;
1112 		buf++;
1113 		RX_DATA_DPRINTF(("%02X %02X ", data & 0xff,
1114 				 (data >> 8) & 0xff));
1115 	}
1116 
1117 	RX_DATA_DPRINTF(("\n"));
1118 	RX_DPRINTF(("Read %d bytes\n", i));
1119 
1120 	*outBuf = m;
1121 	return rx_status;
1122 }
1123 
1124 int
1125 dme_pkt_write_1(struct dme_softc *sc, struct mbuf *bufChain)
1126 {
1127 	int length = 0, i;
1128 	struct mbuf *buf;
1129 	uint8_t *write_ptr;
1130 
1131 	/* We expect that the DM9000 has been setup to accept writes before
1132 	   this function is called. */
1133 
1134 	for (buf = bufChain; buf != NULL; buf = buf->m_next) {
1135 		int to_write = buf->m_len;
1136 
1137 		length += to_write;
1138 
1139 		write_ptr = buf->m_data;
1140 		for (i = 0; i < to_write; i++) {
1141 			bus_space_write_1(sc->sc_iot, sc->sc_ioh,
1142 			    sc->dme_data, *write_ptr);
1143 			write_ptr++;
1144 		}
1145 	} /* for(...) */
1146 
1147 	return length;
1148 }
1149 
1150 int
1151 dme_pkt_read_1(struct dme_softc *sc, struct ifnet *ifp, struct mbuf **outBuf)
1152 {
1153 	uint8_t rx_status;
1154 	struct mbuf *m;
1155 	uint8_t *buf;
1156 	uint16_t frame_length;
1157 	uint16_t i, reg;
1158 	uint8_t data;
1159 
1160 	reg = bus_space_read_1(sc->sc_iot, sc->sc_ioh, sc->dme_data);
1161 	reg |= bus_space_read_1(sc->sc_iot, sc->sc_ioh, sc->dme_data) << 8;
1162 	rx_status = reg & 0xFF;
1163 
1164 	reg = bus_space_read_1(sc->sc_iot, sc->sc_ioh, sc->dme_data);
1165 	reg |= bus_space_read_1(sc->sc_iot, sc->sc_ioh, sc->dme_data) << 8;
1166 	frame_length = reg;
1167 
1168 	if (frame_length > ETHER_MAX_LEN) {
1169 		printf("Got frame of length: %d\n", frame_length);
1170 		printf("ETHER_MAX_LEN is: %d\n", ETHER_MAX_LEN);
1171 		panic("Something is rotten");
1172 	}
1173 	RX_DPRINTF(("dme_receive: "
1174 		    "rx_statux: 0x%x, frame_length: %d\n",
1175 		    rx_status, frame_length));
1176 
1177 
1178 	m = dme_alloc_receive_buffer(ifp, frame_length);
1179 	if (m == NULL) {
1180 		/*
1181 		 * didn't get a receive buffer, so we read the rest of the
1182 		 * packet, throw it away and return an error
1183 		 */
1184 		for (i = 0; i < frame_length; i++ ) {
1185 			data = bus_space_read_2(sc->sc_iot,
1186 					sc->sc_ioh, sc->dme_data);
1187 		}
1188 		*outBuf = NULL;
1189 		return 0;
1190 	}
1191 
1192 	buf = mtod(m, uint8_t *);
1193 
1194 	RX_DPRINTF(("dme_receive: "));
1195 
1196 	for (i = 0; i< frame_length; i += 1 ) {
1197 		data = bus_space_read_1(sc->sc_iot, sc->sc_ioh, sc->dme_data);
1198 		*buf = data;
1199 		buf++;
1200 		RX_DATA_DPRINTF(("%02X ", data));
1201 	}
1202 
1203 	RX_DATA_DPRINTF(("\n"));
1204 	RX_DPRINTF(("Read %d bytes\n", i));
1205 
1206 	*outBuf = m;
1207 	return rx_status;
1208 }
1209 
1210 struct mbuf*
1211 dme_alloc_receive_buffer(struct ifnet *ifp, unsigned int frame_length)
1212 {
1213 	struct dme_softc *sc = ifp->if_softc;
1214 	struct mbuf *m;
1215 	int pad;
1216 
1217 	MGETHDR(m, M_DONTWAIT, MT_DATA);
1218 	if (m == NULL) return NULL;
1219 
1220 	m_set_rcvif(m, ifp);
1221 	/* Ensure that we always allocate an even number of
1222 	 * bytes in order to avoid writing beyond the buffer
1223 	 */
1224 	m->m_pkthdr.len = frame_length + (frame_length % sc->sc_data_width);
1225 	pad = ALIGN(sizeof(struct ether_header)) -
1226 		sizeof(struct ether_header);
1227 	/* All our frames have the CRC attached */
1228 	m->m_flags |= M_HASFCS;
1229 	if (m->m_pkthdr.len + pad > MHLEN) {
1230 		MCLGET(m, M_DONTWAIT);
1231 		if ((m->m_flags & M_EXT) == 0) {
1232 			m_freem(m);
1233 			return NULL;
1234 		}
1235 	}
1236 
1237 	m->m_data += pad;
1238 	m->m_len = frame_length + (frame_length % sc->sc_data_width);
1239 
1240 	return m;
1241 }
1242