xref: /openbsd-src/sys/dev/ic/gem.c (revision e5157e49389faebcb42b7237d55fbf096d9c2523)
1 /*	$OpenBSD: gem.c,v 1.106 2014/08/27 05:54:15 dlg Exp $	*/
2 /*	$NetBSD: gem.c,v 1.1 2001/09/16 00:11:43 eeh Exp $ */
3 
4 /*
5  *
6  * Copyright (C) 2001 Eduardo Horvath.
7  * All rights reserved.
8  *
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR  ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR  BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  */
32 
33 /*
34  * Driver for Sun GEM ethernet controllers.
35  */
36 
37 #include "bpfilter.h"
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/timeout.h>
42 #include <sys/mbuf.h>
43 #include <sys/syslog.h>
44 #include <sys/malloc.h>
45 #include <sys/kernel.h>
46 #include <sys/socket.h>
47 #include <sys/ioctl.h>
48 #include <sys/errno.h>
49 #include <sys/device.h>
50 
51 #include <machine/endian.h>
52 
53 #include <net/if.h>
54 #include <net/if_dl.h>
55 #include <net/if_media.h>
56 
57 #include <netinet/in.h>
58 #include <netinet/if_ether.h>
59 
60 #if NBPFILTER > 0
61 #include <net/bpf.h>
62 #endif
63 
64 #include <machine/bus.h>
65 #include <machine/intr.h>
66 
67 #include <dev/mii/mii.h>
68 #include <dev/mii/miivar.h>
69 #include <dev/mii/mii_bitbang.h>
70 
71 #include <dev/ic/gemreg.h>
72 #include <dev/ic/gemvar.h>
73 
74 #define TRIES	10000
75 
76 struct cfdriver gem_cd = {
77 	NULL, "gem", DV_IFNET
78 };
79 
80 void		gem_start(struct ifnet *);
81 void		gem_stop(struct ifnet *, int);
82 int		gem_ioctl(struct ifnet *, u_long, caddr_t);
83 void		gem_tick(void *);
84 void		gem_watchdog(struct ifnet *);
85 int		gem_init(struct ifnet *);
86 void		gem_init_regs(struct gem_softc *);
87 int		gem_ringsize(int);
88 int		gem_meminit(struct gem_softc *);
89 void		gem_mifinit(struct gem_softc *);
90 int		gem_bitwait(struct gem_softc *, bus_space_handle_t, int,
91 		    u_int32_t, u_int32_t);
92 void		gem_reset(struct gem_softc *);
93 int		gem_reset_rx(struct gem_softc *);
94 int		gem_reset_tx(struct gem_softc *);
95 int		gem_disable_rx(struct gem_softc *);
96 int		gem_disable_tx(struct gem_softc *);
97 void		gem_rx_watchdog(void *);
98 void		gem_rxdrain(struct gem_softc *);
99 void		gem_fill_rx_ring(struct gem_softc *);
100 int		gem_add_rxbuf(struct gem_softc *, int idx);
101 void		gem_iff(struct gem_softc *);
102 
103 /* MII methods & callbacks */
104 int		gem_mii_readreg(struct device *, int, int);
105 void		gem_mii_writereg(struct device *, int, int, int);
106 void		gem_mii_statchg(struct device *);
107 int		gem_pcs_readreg(struct device *, int, int);
108 void		gem_pcs_writereg(struct device *, int, int, int);
109 
110 int		gem_mediachange(struct ifnet *);
111 void		gem_mediastatus(struct ifnet *, struct ifmediareq *);
112 
113 int		gem_eint(struct gem_softc *, u_int);
114 int		gem_rint(struct gem_softc *);
115 int		gem_tint(struct gem_softc *, u_int32_t);
116 int		gem_pint(struct gem_softc *);
117 
118 #ifdef GEM_DEBUG
119 #define	DPRINTF(sc, x)	if ((sc)->sc_arpcom.ac_if.if_flags & IFF_DEBUG) \
120 				printf x
121 #else
122 #define	DPRINTF(sc, x)	/* nothing */
123 #endif
124 
125 /*
126  * Attach a Gem interface to the system.
127  */
128 void
129 gem_config(struct gem_softc *sc)
130 {
131 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
132 	struct mii_data *mii = &sc->sc_mii;
133 	struct mii_softc *child;
134 	int i, error, mii_flags, phyad;
135 	struct ifmedia_entry *ifm;
136 
137 	/* Make sure the chip is stopped. */
138 	ifp->if_softc = sc;
139 	gem_reset(sc);
140 
141 	/*
142 	 * Allocate the control data structures, and create and load the
143 	 * DMA map for it.
144 	 */
145 	if ((error = bus_dmamem_alloc(sc->sc_dmatag,
146 	    sizeof(struct gem_control_data), PAGE_SIZE, 0, &sc->sc_cdseg,
147 	    1, &sc->sc_cdnseg, 0)) != 0) {
148 		printf("\n%s: unable to allocate control data, error = %d\n",
149 		    sc->sc_dev.dv_xname, error);
150 		goto fail_0;
151 	}
152 
153 	/* XXX should map this in with correct endianness */
154 	if ((error = bus_dmamem_map(sc->sc_dmatag, &sc->sc_cdseg, sc->sc_cdnseg,
155 	    sizeof(struct gem_control_data), (caddr_t *)&sc->sc_control_data,
156 	    BUS_DMA_COHERENT)) != 0) {
157 		printf("\n%s: unable to map control data, error = %d\n",
158 		    sc->sc_dev.dv_xname, error);
159 		goto fail_1;
160 	}
161 
162 	if ((error = bus_dmamap_create(sc->sc_dmatag,
163 	    sizeof(struct gem_control_data), 1,
164 	    sizeof(struct gem_control_data), 0, 0, &sc->sc_cddmamap)) != 0) {
165 		printf("\n%s: unable to create control data DMA map, "
166 		    "error = %d\n", sc->sc_dev.dv_xname, error);
167 		goto fail_2;
168 	}
169 
170 	if ((error = bus_dmamap_load(sc->sc_dmatag, sc->sc_cddmamap,
171 	    sc->sc_control_data, sizeof(struct gem_control_data), NULL,
172 	    0)) != 0) {
173 		printf("\n%s: unable to load control data DMA map, error = %d\n",
174 		    sc->sc_dev.dv_xname, error);
175 		goto fail_3;
176 	}
177 
178 	/*
179 	 * Create the receive buffer DMA maps.
180 	 */
181 	for (i = 0; i < GEM_NRXDESC; i++) {
182 		if ((error = bus_dmamap_create(sc->sc_dmatag, MCLBYTES, 1,
183 		    MCLBYTES, 0, 0, &sc->sc_rxsoft[i].rxs_dmamap)) != 0) {
184 			printf("\n%s: unable to create rx DMA map %d, "
185 			    "error = %d\n", sc->sc_dev.dv_xname, i, error);
186 			goto fail_5;
187 		}
188 		sc->sc_rxsoft[i].rxs_mbuf = NULL;
189 	}
190 	/*
191 	 * Create the transmit buffer DMA maps.
192 	 */
193 	for (i = 0; i < GEM_NTXDESC; i++) {
194 		if ((error = bus_dmamap_create(sc->sc_dmatag, MCLBYTES,
195 		    GEM_NTXSEGS, MCLBYTES, 0, BUS_DMA_NOWAIT,
196 		    &sc->sc_txd[i].sd_map)) != 0) {
197 			printf("\n%s: unable to create tx DMA map %d, "
198 			    "error = %d\n", sc->sc_dev.dv_xname, i, error);
199 			goto fail_6;
200 		}
201 		sc->sc_txd[i].sd_mbuf = NULL;
202 	}
203 
204 	/*
205 	 * From this point forward, the attachment cannot fail.  A failure
206 	 * before this point releases all resources that may have been
207 	 * allocated.
208 	 */
209 
210 	/* Announce ourselves. */
211 	printf(", address %s\n", ether_sprintf(sc->sc_arpcom.ac_enaddr));
212 
213 	/* Get RX FIFO size */
214 	sc->sc_rxfifosize = 64 *
215 	    bus_space_read_4(sc->sc_bustag, sc->sc_h1, GEM_RX_FIFO_SIZE);
216 
217 	/* Initialize ifnet structure. */
218 	strlcpy(ifp->if_xname, sc->sc_dev.dv_xname, sizeof ifp->if_xname);
219 	ifp->if_softc = sc;
220 	ifp->if_flags =
221 	    IFF_BROADCAST | IFF_SIMPLEX | IFF_NOTRAILERS | IFF_MULTICAST;
222 	ifp->if_start = gem_start;
223 	ifp->if_ioctl = gem_ioctl;
224 	ifp->if_watchdog = gem_watchdog;
225 	IFQ_SET_MAXLEN(&ifp->if_snd, GEM_NTXDESC - 1);
226 	IFQ_SET_READY(&ifp->if_snd);
227 
228 	ifp->if_capabilities = IFCAP_VLAN_MTU;
229 
230 	/* Initialize ifmedia structures and MII info */
231 	mii->mii_ifp = ifp;
232 	mii->mii_readreg = gem_mii_readreg;
233 	mii->mii_writereg = gem_mii_writereg;
234 	mii->mii_statchg = gem_mii_statchg;
235 
236 	ifmedia_init(&mii->mii_media, 0, gem_mediachange, gem_mediastatus);
237 
238 	/* Bad things will happen if we touch this register on ERI. */
239 	if (sc->sc_variant != GEM_SUN_ERI)
240 		bus_space_write_4(sc->sc_bustag, sc->sc_h1,
241 		    GEM_MII_DATAPATH_MODE, 0);
242 
243 	gem_mifinit(sc);
244 
245 	mii_flags = MIIF_DOPAUSE;
246 
247 	/*
248 	 * Look for an external PHY.
249 	 */
250 	if (sc->sc_mif_config & GEM_MIF_CONFIG_MDI1) {
251 		sc->sc_mif_config |= GEM_MIF_CONFIG_PHY_SEL;
252 		bus_space_write_4(sc->sc_bustag, sc->sc_h1,
253 	            GEM_MIF_CONFIG, sc->sc_mif_config);
254 
255 		switch (sc->sc_variant) {
256 		case GEM_SUN_ERI:
257 			phyad = GEM_PHYAD_EXTERNAL;
258 			break;
259 		default:
260 			phyad = MII_PHY_ANY;
261 			break;
262 		}
263 
264 		mii_attach(&sc->sc_dev, mii, 0xffffffff, phyad,
265 		    MII_OFFSET_ANY, mii_flags);
266 	}
267 
268 	/*
269 	 * Fall back on an internal PHY if no external PHY was found.
270 	 * Note that with Apple (K2) GMACs GEM_MIF_CONFIG_MDI0 can't be
271 	 * trusted when the firmware has powered down the chip
272 	 */
273 	child = LIST_FIRST(&mii->mii_phys);
274 	if (child == NULL &&
275 	    (sc->sc_mif_config & GEM_MIF_CONFIG_MDI0 || GEM_IS_APPLE(sc))) {
276 		sc->sc_mif_config &= ~GEM_MIF_CONFIG_PHY_SEL;
277 		bus_space_write_4(sc->sc_bustag, sc->sc_h1,
278 	            GEM_MIF_CONFIG, sc->sc_mif_config);
279 
280 		switch (sc->sc_variant) {
281 		case GEM_SUN_ERI:
282 		case GEM_APPLE_K2_GMAC:
283 			phyad = GEM_PHYAD_INTERNAL;
284 			break;
285 		case GEM_APPLE_GMAC:
286 			phyad = GEM_PHYAD_EXTERNAL;
287 			break;
288 		default:
289 			phyad = MII_PHY_ANY;
290 			break;
291 		}
292 
293 		mii_attach(&sc->sc_dev, mii, 0xffffffff, phyad,
294 		    MII_OFFSET_ANY, mii_flags);
295 	}
296 
297 	/*
298 	 * Try the external PCS SERDES if we didn't find any MII
299 	 * devices.
300 	 */
301 	child = LIST_FIRST(&mii->mii_phys);
302 	if (child == NULL && sc->sc_variant != GEM_SUN_ERI) {
303 		bus_space_write_4(sc->sc_bustag, sc->sc_h1,
304 		    GEM_MII_DATAPATH_MODE, GEM_MII_DATAPATH_SERDES);
305 
306 		bus_space_write_4(sc->sc_bustag, sc->sc_h1,
307 		    GEM_MII_SLINK_CONTROL,
308 		    GEM_MII_SLINK_LOOPBACK|GEM_MII_SLINK_EN_SYNC_D);
309 
310 		bus_space_write_4(sc->sc_bustag, sc->sc_h1,
311 		     GEM_MII_CONFIG, GEM_MII_CONFIG_ENABLE);
312 
313 		mii->mii_readreg = gem_pcs_readreg;
314 		mii->mii_writereg = gem_pcs_writereg;
315 
316 		mii_flags |= MIIF_NOISOLATE;
317 
318 		mii_attach(&sc->sc_dev, mii, 0xffffffff, MII_PHY_ANY,
319 		    MII_OFFSET_ANY, mii_flags);
320 	}
321 
322 	child = LIST_FIRST(&mii->mii_phys);
323 	if (child == NULL) {
324 		/* No PHY attached */
325 		ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
326 		ifmedia_set(&sc->sc_media, IFM_ETHER|IFM_MANUAL);
327 	} else {
328 		/*
329 		 * XXX - we can really do the following ONLY if the
330 		 * phy indeed has the auto negotiation capability!!
331 		 */
332 		ifmedia_set(&sc->sc_media, IFM_ETHER|IFM_AUTO);
333 	}
334 
335 	/* Check if we support GigE media. */
336 	TAILQ_FOREACH(ifm, &sc->sc_media.ifm_list, ifm_list) {
337 		if (IFM_SUBTYPE(ifm->ifm_media) == IFM_1000_T ||
338 		    IFM_SUBTYPE(ifm->ifm_media) == IFM_1000_SX ||
339 		    IFM_SUBTYPE(ifm->ifm_media) == IFM_1000_LX ||
340 		    IFM_SUBTYPE(ifm->ifm_media) == IFM_1000_CX) {
341 			sc->sc_flags |= GEM_GIGABIT;
342 			break;
343 		}
344 	}
345 
346 	/* Attach the interface. */
347 	if_attach(ifp);
348 	ether_ifattach(ifp);
349 
350 	timeout_set(&sc->sc_tick_ch, gem_tick, sc);
351 	timeout_set(&sc->sc_rx_watchdog, gem_rx_watchdog, sc);
352 	return;
353 
354 	/*
355 	 * Free any resources we've allocated during the failed attach
356 	 * attempt.  Do this in reverse order and fall through.
357 	 */
358  fail_6:
359 	for (i = 0; i < GEM_NTXDESC; i++) {
360 		if (sc->sc_txd[i].sd_map != NULL)
361 			bus_dmamap_destroy(sc->sc_dmatag,
362 			    sc->sc_txd[i].sd_map);
363 	}
364  fail_5:
365 	for (i = 0; i < GEM_NRXDESC; i++) {
366 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
367 			bus_dmamap_destroy(sc->sc_dmatag,
368 			    sc->sc_rxsoft[i].rxs_dmamap);
369 	}
370 	bus_dmamap_unload(sc->sc_dmatag, sc->sc_cddmamap);
371  fail_3:
372 	bus_dmamap_destroy(sc->sc_dmatag, sc->sc_cddmamap);
373  fail_2:
374 	bus_dmamem_unmap(sc->sc_dmatag, (caddr_t)sc->sc_control_data,
375 	    sizeof(struct gem_control_data));
376  fail_1:
377 	bus_dmamem_free(sc->sc_dmatag, &sc->sc_cdseg, sc->sc_cdnseg);
378  fail_0:
379 	return;
380 }
381 
382 void
383 gem_unconfig(struct gem_softc *sc)
384 {
385 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
386 	int i;
387 
388 	gem_stop(ifp, 1);
389 
390 	for (i = 0; i < GEM_NTXDESC; i++) {
391 		if (sc->sc_txd[i].sd_map != NULL)
392 			bus_dmamap_destroy(sc->sc_dmatag,
393 			    sc->sc_txd[i].sd_map);
394 	}
395 	for (i = 0; i < GEM_NRXDESC; i++) {
396 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
397 			bus_dmamap_destroy(sc->sc_dmatag,
398 			    sc->sc_rxsoft[i].rxs_dmamap);
399 	}
400 	bus_dmamap_unload(sc->sc_dmatag, sc->sc_cddmamap);
401 	bus_dmamap_destroy(sc->sc_dmatag, sc->sc_cddmamap);
402 	bus_dmamem_unmap(sc->sc_dmatag, (caddr_t)sc->sc_control_data,
403 	    sizeof(struct gem_control_data));
404 	bus_dmamem_free(sc->sc_dmatag, &sc->sc_cdseg, sc->sc_cdnseg);
405 
406 	/* Detach all PHYs */
407 	mii_detach(&sc->sc_mii, MII_PHY_ANY, MII_OFFSET_ANY);
408 
409 	/* Delete all remaining media. */
410 	ifmedia_delete_instance(&sc->sc_mii.mii_media, IFM_INST_ANY);
411 
412 	ether_ifdetach(ifp);
413 	if_detach(ifp);
414 }
415 
416 
417 void
418 gem_tick(void *arg)
419 {
420 	struct gem_softc *sc = arg;
421 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
422 	bus_space_tag_t t = sc->sc_bustag;
423 	bus_space_handle_t mac = sc->sc_h1;
424 	int s;
425 	u_int32_t v;
426 
427 	/* unload collisions counters */
428 	v = bus_space_read_4(t, mac, GEM_MAC_EXCESS_COLL_CNT) +
429 	    bus_space_read_4(t, mac, GEM_MAC_LATE_COLL_CNT);
430 	ifp->if_collisions += v +
431 	    bus_space_read_4(t, mac, GEM_MAC_NORM_COLL_CNT) +
432 	    bus_space_read_4(t, mac, GEM_MAC_FIRST_COLL_CNT);
433 	ifp->if_oerrors += v;
434 
435 	/* read error counters */
436 	ifp->if_ierrors +=
437 	    bus_space_read_4(t, mac, GEM_MAC_RX_LEN_ERR_CNT) +
438 	    bus_space_read_4(t, mac, GEM_MAC_RX_ALIGN_ERR) +
439 	    bus_space_read_4(t, mac, GEM_MAC_RX_CRC_ERR_CNT) +
440 	    bus_space_read_4(t, mac, GEM_MAC_RX_CODE_VIOL);
441 
442 	/* clear the hardware counters */
443 	bus_space_write_4(t, mac, GEM_MAC_NORM_COLL_CNT, 0);
444 	bus_space_write_4(t, mac, GEM_MAC_FIRST_COLL_CNT, 0);
445 	bus_space_write_4(t, mac, GEM_MAC_EXCESS_COLL_CNT, 0);
446 	bus_space_write_4(t, mac, GEM_MAC_LATE_COLL_CNT, 0);
447 	bus_space_write_4(t, mac, GEM_MAC_RX_LEN_ERR_CNT, 0);
448 	bus_space_write_4(t, mac, GEM_MAC_RX_ALIGN_ERR, 0);
449 	bus_space_write_4(t, mac, GEM_MAC_RX_CRC_ERR_CNT, 0);
450 	bus_space_write_4(t, mac, GEM_MAC_RX_CODE_VIOL, 0);
451 
452 	s = splnet();
453 	mii_tick(&sc->sc_mii);
454 	splx(s);
455 
456 	timeout_add_sec(&sc->sc_tick_ch, 1);
457 }
458 
459 int
460 gem_bitwait(struct gem_softc *sc, bus_space_handle_t h, int r,
461    u_int32_t clr, u_int32_t set)
462 {
463 	int i;
464 	u_int32_t reg;
465 
466 	for (i = TRIES; i--; DELAY(100)) {
467 		reg = bus_space_read_4(sc->sc_bustag, h, r);
468 		if ((reg & clr) == 0 && (reg & set) == set)
469 			return (1);
470 	}
471 
472 	return (0);
473 }
474 
475 void
476 gem_reset(struct gem_softc *sc)
477 {
478 	bus_space_tag_t t = sc->sc_bustag;
479 	bus_space_handle_t h = sc->sc_h2;
480 	int s;
481 
482 	s = splnet();
483 	DPRINTF(sc, ("%s: gem_reset\n", sc->sc_dev.dv_xname));
484 	gem_reset_rx(sc);
485 	gem_reset_tx(sc);
486 
487 	/* Do a full reset */
488 	bus_space_write_4(t, h, GEM_RESET, GEM_RESET_RX|GEM_RESET_TX);
489 	if (!gem_bitwait(sc, h, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX, 0))
490 		printf("%s: cannot reset device\n", sc->sc_dev.dv_xname);
491 	splx(s);
492 }
493 
494 
495 /*
496  * Drain the receive queue.
497  */
498 void
499 gem_rxdrain(struct gem_softc *sc)
500 {
501 	struct gem_rxsoft *rxs;
502 	int i;
503 
504 	for (i = 0; i < GEM_NRXDESC; i++) {
505 		rxs = &sc->sc_rxsoft[i];
506 		if (rxs->rxs_mbuf != NULL) {
507 			bus_dmamap_sync(sc->sc_dmatag, rxs->rxs_dmamap, 0,
508 			    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);
509 			bus_dmamap_unload(sc->sc_dmatag, rxs->rxs_dmamap);
510 			m_freem(rxs->rxs_mbuf);
511 			rxs->rxs_mbuf = NULL;
512 		}
513 	}
514 	sc->sc_rx_prod = sc->sc_rx_cons = 0;
515 }
516 
517 /*
518  * Reset the whole thing.
519  */
520 void
521 gem_stop(struct ifnet *ifp, int softonly)
522 {
523 	struct gem_softc *sc = (struct gem_softc *)ifp->if_softc;
524 	struct gem_sxd *sd;
525 	u_int32_t i;
526 
527 	DPRINTF(sc, ("%s: gem_stop\n", sc->sc_dev.dv_xname));
528 
529 	timeout_del(&sc->sc_tick_ch);
530 
531 	/*
532 	 * Mark the interface down and cancel the watchdog timer.
533 	 */
534 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
535 	ifp->if_timer = 0;
536 
537 	if (!softonly) {
538 		mii_down(&sc->sc_mii);
539 
540 		gem_reset_rx(sc);
541 		gem_reset_tx(sc);
542 	}
543 
544 	/*
545 	 * Release any queued transmit buffers.
546 	 */
547 	for (i = 0; i < GEM_NTXDESC; i++) {
548 		sd = &sc->sc_txd[i];
549 		if (sd->sd_mbuf != NULL) {
550 			bus_dmamap_sync(sc->sc_dmatag, sd->sd_map, 0,
551 			    sd->sd_map->dm_mapsize, BUS_DMASYNC_POSTWRITE);
552 			bus_dmamap_unload(sc->sc_dmatag, sd->sd_map);
553 			m_freem(sd->sd_mbuf);
554 			sd->sd_mbuf = NULL;
555 		}
556 	}
557 	sc->sc_tx_cnt = sc->sc_tx_prod = sc->sc_tx_cons = 0;
558 
559 	gem_rxdrain(sc);
560 }
561 
562 
563 /*
564  * Reset the receiver
565  */
566 int
567 gem_reset_rx(struct gem_softc *sc)
568 {
569 	bus_space_tag_t t = sc->sc_bustag;
570 	bus_space_handle_t h = sc->sc_h1, h2 = sc->sc_h2;
571 
572 	/*
573 	 * Resetting while DMA is in progress can cause a bus hang, so we
574 	 * disable DMA first.
575 	 */
576 	gem_disable_rx(sc);
577 	bus_space_write_4(t, h, GEM_RX_CONFIG, 0);
578 	/* Wait till it finishes */
579 	if (!gem_bitwait(sc, h, GEM_RX_CONFIG, 1, 0))
580 		printf("%s: cannot disable rx dma\n", sc->sc_dev.dv_xname);
581 	/* Wait 5ms extra. */
582 	delay(5000);
583 
584 	/* Finally, reset the ERX */
585 	bus_space_write_4(t, h2, GEM_RESET, GEM_RESET_RX);
586 	/* Wait till it finishes */
587 	if (!gem_bitwait(sc, h2, GEM_RESET, GEM_RESET_RX, 0)) {
588 		printf("%s: cannot reset receiver\n", sc->sc_dev.dv_xname);
589 		return (1);
590 	}
591 	return (0);
592 }
593 
594 
595 /*
596  * Reset the transmitter
597  */
598 int
599 gem_reset_tx(struct gem_softc *sc)
600 {
601 	bus_space_tag_t t = sc->sc_bustag;
602 	bus_space_handle_t h = sc->sc_h1, h2 = sc->sc_h2;
603 
604 	/*
605 	 * Resetting while DMA is in progress can cause a bus hang, so we
606 	 * disable DMA first.
607 	 */
608 	gem_disable_tx(sc);
609 	bus_space_write_4(t, h, GEM_TX_CONFIG, 0);
610 	/* Wait till it finishes */
611 	if (!gem_bitwait(sc, h, GEM_TX_CONFIG, 1, 0))
612 		printf("%s: cannot disable tx dma\n", sc->sc_dev.dv_xname);
613 	/* Wait 5ms extra. */
614 	delay(5000);
615 
616 	/* Finally, reset the ETX */
617 	bus_space_write_4(t, h2, GEM_RESET, GEM_RESET_TX);
618 	/* Wait till it finishes */
619 	if (!gem_bitwait(sc, h2, GEM_RESET, GEM_RESET_TX, 0)) {
620 		printf("%s: cannot reset transmitter\n",
621 			sc->sc_dev.dv_xname);
622 		return (1);
623 	}
624 	return (0);
625 }
626 
627 /*
628  * Disable receiver.
629  */
630 int
631 gem_disable_rx(struct gem_softc *sc)
632 {
633 	bus_space_tag_t t = sc->sc_bustag;
634 	bus_space_handle_t h = sc->sc_h1;
635 	u_int32_t cfg;
636 
637 	/* Flip the enable bit */
638 	cfg = bus_space_read_4(t, h, GEM_MAC_RX_CONFIG);
639 	cfg &= ~GEM_MAC_RX_ENABLE;
640 	bus_space_write_4(t, h, GEM_MAC_RX_CONFIG, cfg);
641 
642 	/* Wait for it to finish */
643 	return (gem_bitwait(sc, h, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0));
644 }
645 
646 /*
647  * Disable transmitter.
648  */
649 int
650 gem_disable_tx(struct gem_softc *sc)
651 {
652 	bus_space_tag_t t = sc->sc_bustag;
653 	bus_space_handle_t h = sc->sc_h1;
654 	u_int32_t cfg;
655 
656 	/* Flip the enable bit */
657 	cfg = bus_space_read_4(t, h, GEM_MAC_TX_CONFIG);
658 	cfg &= ~GEM_MAC_TX_ENABLE;
659 	bus_space_write_4(t, h, GEM_MAC_TX_CONFIG, cfg);
660 
661 	/* Wait for it to finish */
662 	return (gem_bitwait(sc, h, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0));
663 }
664 
665 /*
666  * Initialize interface.
667  */
668 int
669 gem_meminit(struct gem_softc *sc)
670 {
671 	int i;
672 
673 	/*
674 	 * Initialize the transmit descriptor ring.
675 	 */
676 	for (i = 0; i < GEM_NTXDESC; i++) {
677 		sc->sc_txdescs[i].gd_flags = 0;
678 		sc->sc_txdescs[i].gd_addr = 0;
679 	}
680 	GEM_CDTXSYNC(sc, 0, GEM_NTXDESC,
681 	    BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
682 
683 	/*
684 	 * Initialize the receive descriptor and receive job
685 	 * descriptor rings.
686 	 */
687 	for (i = 0; i < GEM_NRXDESC; i++) {
688 		sc->sc_rxdescs[i].gd_flags = 0;
689 		sc->sc_rxdescs[i].gd_addr = 0;
690 	}
691 	/* Hardware reads RX descriptors in multiples of four. */
692 	if_rxr_init(&sc->sc_rx_ring, 4, GEM_NRXDESC - 4);
693 	gem_fill_rx_ring(sc);
694 
695 	return (0);
696 }
697 
698 int
699 gem_ringsize(int sz)
700 {
701 	switch (sz) {
702 	case 32:
703 		return GEM_RING_SZ_32;
704 	case 64:
705 		return GEM_RING_SZ_64;
706 	case 128:
707 		return GEM_RING_SZ_128;
708 	case 256:
709 		return GEM_RING_SZ_256;
710 	case 512:
711 		return GEM_RING_SZ_512;
712 	case 1024:
713 		return GEM_RING_SZ_1024;
714 	case 2048:
715 		return GEM_RING_SZ_2048;
716 	case 4096:
717 		return GEM_RING_SZ_4096;
718 	case 8192:
719 		return GEM_RING_SZ_8192;
720 	default:
721 		printf("gem: invalid Receive Descriptor ring size %d\n", sz);
722 		return GEM_RING_SZ_32;
723 	}
724 }
725 
726 /*
727  * Initialization of interface; set up initialization block
728  * and transmit/receive descriptor rings.
729  */
730 int
731 gem_init(struct ifnet *ifp)
732 {
733 
734 	struct gem_softc *sc = (struct gem_softc *)ifp->if_softc;
735 	bus_space_tag_t t = sc->sc_bustag;
736 	bus_space_handle_t h = sc->sc_h1;
737 	int s;
738 	u_int32_t v;
739 
740 	s = splnet();
741 
742 	DPRINTF(sc, ("%s: gem_init: calling stop\n", sc->sc_dev.dv_xname));
743 	/*
744 	 * Initialization sequence. The numbered steps below correspond
745 	 * to the sequence outlined in section 6.3.5.1 in the Ethernet
746 	 * Channel Engine manual (part of the PCIO manual).
747 	 * See also the STP2002-STQ document from Sun Microsystems.
748 	 */
749 
750 	/* step 1 & 2. Reset the Ethernet Channel */
751 	gem_stop(ifp, 0);
752 	gem_reset(sc);
753 	DPRINTF(sc, ("%s: gem_init: restarting\n", sc->sc_dev.dv_xname));
754 
755 	/* Re-initialize the MIF */
756 	gem_mifinit(sc);
757 
758 	/* Call MI reset function if any */
759 	if (sc->sc_hwreset)
760 		(*sc->sc_hwreset)(sc);
761 
762 	/* step 3. Setup data structures in host memory */
763 	gem_meminit(sc);
764 
765 	/* step 4. TX MAC registers & counters */
766 	gem_init_regs(sc);
767 
768 	/* step 5. RX MAC registers & counters */
769 	gem_iff(sc);
770 
771 	/* step 6 & 7. Program Descriptor Ring Base Addresses */
772 	bus_space_write_4(t, h, GEM_TX_RING_PTR_HI,
773 	    (((uint64_t)GEM_CDTXADDR(sc,0)) >> 32));
774 	bus_space_write_4(t, h, GEM_TX_RING_PTR_LO, GEM_CDTXADDR(sc, 0));
775 
776 	bus_space_write_4(t, h, GEM_RX_RING_PTR_HI,
777 	    (((uint64_t)GEM_CDRXADDR(sc,0)) >> 32));
778 	bus_space_write_4(t, h, GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
779 
780 	/* step 8. Global Configuration & Interrupt Mask */
781 	bus_space_write_4(t, h, GEM_INTMASK,
782 		      ~(GEM_INTR_TX_INTME|
783 			GEM_INTR_TX_EMPTY|
784 			GEM_INTR_RX_DONE|GEM_INTR_RX_NOBUF|
785 			GEM_INTR_RX_TAG_ERR|GEM_INTR_PCS|
786 			GEM_INTR_MAC_CONTROL|GEM_INTR_MIF|
787 			GEM_INTR_BERR));
788 	bus_space_write_4(t, h, GEM_MAC_RX_MASK,
789 	    GEM_MAC_RX_DONE|GEM_MAC_RX_FRAME_CNT);
790 	bus_space_write_4(t, h, GEM_MAC_TX_MASK, 0xffff); /* XXXX */
791 	bus_space_write_4(t, h, GEM_MAC_CONTROL_MASK, 0); /* XXXX */
792 
793 	/* step 9. ETX Configuration: use mostly default values */
794 
795 	/* Enable DMA */
796 	v = gem_ringsize(GEM_NTXDESC /*XXX*/);
797 	v |= ((sc->sc_variant == GEM_SUN_ERI ? 0x100 : 0x04ff) << 10) &
798 	    GEM_TX_CONFIG_TXFIFO_TH;
799 	bus_space_write_4(t, h, GEM_TX_CONFIG, v | GEM_TX_CONFIG_TXDMA_EN);
800 	bus_space_write_4(t, h, GEM_TX_KICK, 0);
801 
802 	/* step 10. ERX Configuration */
803 
804 	/* Encode Receive Descriptor ring size: four possible values */
805 	v = gem_ringsize(GEM_NRXDESC /*XXX*/);
806 	/* Enable DMA */
807 	bus_space_write_4(t, h, GEM_RX_CONFIG,
808 		v|(GEM_THRSH_1024<<GEM_RX_CONFIG_FIFO_THRS_SHIFT)|
809 		(2<<GEM_RX_CONFIG_FBOFF_SHFT)|GEM_RX_CONFIG_RXDMA_EN|
810 		(0<<GEM_RX_CONFIG_CXM_START_SHFT));
811 	/*
812 	 * The following value is for an OFF Threshold of about 3/4 full
813 	 * and an ON Threshold of 1/4 full.
814 	 */
815 	bus_space_write_4(t, h, GEM_RX_PAUSE_THRESH,
816 	    (3 * sc->sc_rxfifosize / 256) |
817 	    ((sc->sc_rxfifosize / 256) << 12));
818 	bus_space_write_4(t, h, GEM_RX_BLANKING, (6 << 12) | 6);
819 
820 	/* step 11. Configure Media */
821 	mii_mediachg(&sc->sc_mii);
822 
823 	/* step 12. RX_MAC Configuration Register */
824 	v = bus_space_read_4(t, h, GEM_MAC_RX_CONFIG);
825 	v |= GEM_MAC_RX_ENABLE | GEM_MAC_RX_STRIP_CRC;
826 	bus_space_write_4(t, h, GEM_MAC_RX_CONFIG, v);
827 
828 	/* step 14. Issue Transmit Pending command */
829 
830 	/* Call MI initialization function if any */
831 	if (sc->sc_hwinit)
832 		(*sc->sc_hwinit)(sc);
833 
834 	/* step 15.  Give the receiver a swift kick */
835 	bus_space_write_4(t, h, GEM_RX_KICK, sc->sc_rx_prod);
836 
837 	/* Start the one second timer. */
838 	timeout_add_sec(&sc->sc_tick_ch, 1);
839 
840 	ifp->if_flags |= IFF_RUNNING;
841 	ifp->if_flags &= ~IFF_OACTIVE;
842 
843 	splx(s);
844 
845 	return (0);
846 }
847 
848 void
849 gem_init_regs(struct gem_softc *sc)
850 {
851 	bus_space_tag_t t = sc->sc_bustag;
852 	bus_space_handle_t h = sc->sc_h1;
853 	u_int32_t v;
854 
855 	/* These regs are not cleared on reset */
856 	sc->sc_inited = 0;
857 	if (!sc->sc_inited) {
858 		/* Load recommended values */
859 		bus_space_write_4(t, h, GEM_MAC_IPG0, 0x00);
860 		bus_space_write_4(t, h, GEM_MAC_IPG1, 0x08);
861 		bus_space_write_4(t, h, GEM_MAC_IPG2, 0x04);
862 
863 		bus_space_write_4(t, h, GEM_MAC_MAC_MIN_FRAME, ETHER_MIN_LEN);
864 		/* Max frame and max burst size */
865 		bus_space_write_4(t, h, GEM_MAC_MAC_MAX_FRAME,
866 		    (ETHER_MAX_LEN + ETHER_VLAN_ENCAP_LEN) | (0x2000 << 16));
867 
868 		bus_space_write_4(t, h, GEM_MAC_PREAMBLE_LEN, 0x07);
869 		bus_space_write_4(t, h, GEM_MAC_JAM_SIZE, 0x04);
870 		bus_space_write_4(t, h, GEM_MAC_ATTEMPT_LIMIT, 0x10);
871 		bus_space_write_4(t, h, GEM_MAC_CONTROL_TYPE, 0x8088);
872 		bus_space_write_4(t, h, GEM_MAC_RANDOM_SEED,
873 		    ((sc->sc_arpcom.ac_enaddr[5]<<8)|sc->sc_arpcom.ac_enaddr[4])&0x3ff);
874 
875 		/* Secondary MAC addr set to 0:0:0:0:0:0 */
876 		bus_space_write_4(t, h, GEM_MAC_ADDR3, 0);
877 		bus_space_write_4(t, h, GEM_MAC_ADDR4, 0);
878 		bus_space_write_4(t, h, GEM_MAC_ADDR5, 0);
879 
880 		/* MAC control addr set to 0:1:c2:0:1:80 */
881 		bus_space_write_4(t, h, GEM_MAC_ADDR6, 0x0001);
882 		bus_space_write_4(t, h, GEM_MAC_ADDR7, 0xc200);
883 		bus_space_write_4(t, h, GEM_MAC_ADDR8, 0x0180);
884 
885 		/* MAC filter addr set to 0:0:0:0:0:0 */
886 		bus_space_write_4(t, h, GEM_MAC_ADDR_FILTER0, 0);
887 		bus_space_write_4(t, h, GEM_MAC_ADDR_FILTER1, 0);
888 		bus_space_write_4(t, h, GEM_MAC_ADDR_FILTER2, 0);
889 
890 		bus_space_write_4(t, h, GEM_MAC_ADR_FLT_MASK1_2, 0);
891 		bus_space_write_4(t, h, GEM_MAC_ADR_FLT_MASK0, 0);
892 
893 		sc->sc_inited = 1;
894 	}
895 
896 	/* Counters need to be zeroed */
897 	bus_space_write_4(t, h, GEM_MAC_NORM_COLL_CNT, 0);
898 	bus_space_write_4(t, h, GEM_MAC_FIRST_COLL_CNT, 0);
899 	bus_space_write_4(t, h, GEM_MAC_EXCESS_COLL_CNT, 0);
900 	bus_space_write_4(t, h, GEM_MAC_LATE_COLL_CNT, 0);
901 	bus_space_write_4(t, h, GEM_MAC_DEFER_TMR_CNT, 0);
902 	bus_space_write_4(t, h, GEM_MAC_PEAK_ATTEMPTS, 0);
903 	bus_space_write_4(t, h, GEM_MAC_RX_FRAME_COUNT, 0);
904 	bus_space_write_4(t, h, GEM_MAC_RX_LEN_ERR_CNT, 0);
905 	bus_space_write_4(t, h, GEM_MAC_RX_ALIGN_ERR, 0);
906 	bus_space_write_4(t, h, GEM_MAC_RX_CRC_ERR_CNT, 0);
907 	bus_space_write_4(t, h, GEM_MAC_RX_CODE_VIOL, 0);
908 
909 	/* Set XOFF PAUSE time */
910 	bus_space_write_4(t, h, GEM_MAC_SEND_PAUSE_CMD, 0x1bf0);
911 
912 	/*
913 	 * Set the internal arbitration to "infinite" bursts of the
914 	 * maximum length of 31 * 64 bytes so DMA transfers aren't
915 	 * split up in cache line size chunks. This greatly improves
916 	 * especially RX performance.
917 	 * Enable silicon bug workarounds for the Apple variants.
918 	 */
919 	v = GEM_CONFIG_TXDMA_LIMIT | GEM_CONFIG_RXDMA_LIMIT;
920 	if (sc->sc_pci)
921 		v |= GEM_CONFIG_BURST_INF;
922 	else
923 		v |= GEM_CONFIG_BURST_64;
924 	if (sc->sc_variant != GEM_SUN_GEM && sc->sc_variant != GEM_SUN_ERI)
925 		v |= GEM_CONFIG_RONPAULBIT | GEM_CONFIG_BUG2FIX;
926 	bus_space_write_4(t, h, GEM_CONFIG, v);
927 
928 	/*
929 	 * Set the station address.
930 	 */
931 	bus_space_write_4(t, h, GEM_MAC_ADDR0,
932 		(sc->sc_arpcom.ac_enaddr[4]<<8) | sc->sc_arpcom.ac_enaddr[5]);
933 	bus_space_write_4(t, h, GEM_MAC_ADDR1,
934 		(sc->sc_arpcom.ac_enaddr[2]<<8) | sc->sc_arpcom.ac_enaddr[3]);
935 	bus_space_write_4(t, h, GEM_MAC_ADDR2,
936 		(sc->sc_arpcom.ac_enaddr[0]<<8) | sc->sc_arpcom.ac_enaddr[1]);
937 }
938 
939 /*
940  * Receive interrupt.
941  */
942 int
943 gem_rint(struct gem_softc *sc)
944 {
945 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
946 	bus_space_tag_t t = sc->sc_bustag;
947 	bus_space_handle_t h = sc->sc_h1;
948 	struct gem_rxsoft *rxs;
949 	struct mbuf *m;
950 	u_int64_t rxstat;
951 	int i, len;
952 
953 	for (i = sc->sc_rx_cons; if_rxr_inuse(&sc->sc_rx_ring) > 0;
954 	    i = GEM_NEXTRX(i)) {
955 		rxs = &sc->sc_rxsoft[i];
956 
957 		GEM_CDRXSYNC(sc, i,
958 		    BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
959 
960 		rxstat = GEM_DMA_READ(sc, &sc->sc_rxdescs[i].gd_flags);
961 
962 		if (rxstat & GEM_RD_OWN) {
963 			/* We have processed all of the receive buffers. */
964 			break;
965 		}
966 
967 		bus_dmamap_sync(sc->sc_dmatag, rxs->rxs_dmamap, 0,
968 		    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);
969 		bus_dmamap_unload(sc->sc_dmatag, rxs->rxs_dmamap);
970 
971 		m = rxs->rxs_mbuf;
972 		rxs->rxs_mbuf = NULL;
973 
974 		if_rxr_put(&sc->sc_rx_ring, 1);
975 
976 		if (rxstat & GEM_RD_BAD_CRC) {
977 			ifp->if_ierrors++;
978 #ifdef GEM_DEBUG
979 			printf("%s: receive error: CRC error\n",
980 				sc->sc_dev.dv_xname);
981 #endif
982 			m_freem(m);
983 			continue;
984 		}
985 
986 #ifdef GEM_DEBUG
987 		if (ifp->if_flags & IFF_DEBUG) {
988 			printf("    rxsoft %p descriptor %d: ", rxs, i);
989 			printf("gd_flags: 0x%016llx\t", (long long)
990 				GEM_DMA_READ(sc, &sc->sc_rxdescs[i].gd_flags));
991 			printf("gd_addr: 0x%016llx\n", (long long)
992 				GEM_DMA_READ(sc, &sc->sc_rxdescs[i].gd_addr));
993 		}
994 #endif
995 
996 		/* No errors; receive the packet. */
997 		len = GEM_RD_BUFLEN(rxstat);
998 
999 		m->m_data += 2; /* We're already off by two */
1000 
1001 		ifp->if_ipackets++;
1002 		m->m_pkthdr.rcvif = ifp;
1003 		m->m_pkthdr.len = m->m_len = len;
1004 
1005 #if NBPFILTER > 0
1006 		if (ifp->if_bpf)
1007 			bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_IN);
1008 #endif /* NBPFILTER > 0 */
1009 
1010 		/* Pass it on. */
1011 		ether_input_mbuf(ifp, m);
1012 	}
1013 
1014 	/* Update the receive pointer. */
1015 	sc->sc_rx_cons = i;
1016 	gem_fill_rx_ring(sc);
1017 	bus_space_write_4(t, h, GEM_RX_KICK, sc->sc_rx_prod);
1018 
1019 	DPRINTF(sc, ("gem_rint: done sc->sc_rx_cons %d, complete %d\n",
1020 		sc->sc_rx_cons, bus_space_read_4(t, h, GEM_RX_COMPLETION)));
1021 
1022 	return (1);
1023 }
1024 
1025 void
1026 gem_fill_rx_ring(struct gem_softc *sc)
1027 {
1028 	u_int slots;
1029 
1030 	for (slots = if_rxr_get(&sc->sc_rx_ring, GEM_NRXDESC - 4);
1031 	    slots > 0; slots--) {
1032 		if (gem_add_rxbuf(sc, sc->sc_rx_prod))
1033 			break;
1034 	}
1035 	if_rxr_put(&sc->sc_rx_ring, slots);
1036 }
1037 
1038 /*
1039  * Add a receive buffer to the indicated descriptor.
1040  */
1041 int
1042 gem_add_rxbuf(struct gem_softc *sc, int idx)
1043 {
1044 	struct gem_rxsoft *rxs = &sc->sc_rxsoft[idx];
1045 	struct mbuf *m;
1046 	int error;
1047 
1048 	m = MCLGETI(NULL, M_DONTWAIT, NULL, MCLBYTES);
1049 	if (!m)
1050 		return (ENOBUFS);
1051 	m->m_len = m->m_pkthdr.len = MCLBYTES;
1052 
1053 #ifdef GEM_DEBUG
1054 /* bzero the packet to check dma */
1055 	memset(m->m_ext.ext_buf, 0, m->m_ext.ext_size);
1056 #endif
1057 
1058 	rxs->rxs_mbuf = m;
1059 
1060 	error = bus_dmamap_load_mbuf(sc->sc_dmatag, rxs->rxs_dmamap, m,
1061 	    BUS_DMA_READ|BUS_DMA_NOWAIT);
1062 	if (error) {
1063 		printf("%s: can't load rx DMA map %d, error = %d\n",
1064 		    sc->sc_dev.dv_xname, idx, error);
1065 		panic("gem_add_rxbuf");	/* XXX */
1066 	}
1067 
1068 	bus_dmamap_sync(sc->sc_dmatag, rxs->rxs_dmamap, 0,
1069 	    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_PREREAD);
1070 
1071 	GEM_INIT_RXDESC(sc, idx);
1072 
1073 	sc->sc_rx_prod = GEM_NEXTRX(sc->sc_rx_prod);
1074 
1075 	return (0);
1076 }
1077 
1078 int
1079 gem_eint(struct gem_softc *sc, u_int status)
1080 {
1081 	if ((status & GEM_INTR_MIF) != 0) {
1082 #ifdef GEM_DEBUG
1083 		printf("%s: link status changed\n", sc->sc_dev.dv_xname);
1084 #endif
1085 		return (1);
1086 	}
1087 
1088 	printf("%s: status=%b\n", sc->sc_dev.dv_xname, status, GEM_INTR_BITS);
1089 	return (1);
1090 }
1091 
1092 int
1093 gem_pint(struct gem_softc *sc)
1094 {
1095 	bus_space_tag_t t = sc->sc_bustag;
1096 	bus_space_handle_t seb = sc->sc_h1;
1097 	u_int32_t status;
1098 
1099 	status = bus_space_read_4(t, seb, GEM_MII_INTERRUP_STATUS);
1100 	status |= bus_space_read_4(t, seb, GEM_MII_INTERRUP_STATUS);
1101 #ifdef GEM_DEBUG
1102 	if (status)
1103 		printf("%s: link status changed\n", sc->sc_dev.dv_xname);
1104 #endif
1105 	return (1);
1106 }
1107 
1108 int
1109 gem_intr(void *v)
1110 {
1111 	struct gem_softc *sc = (struct gem_softc *)v;
1112 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
1113 	bus_space_tag_t t = sc->sc_bustag;
1114 	bus_space_handle_t seb = sc->sc_h1;
1115 	u_int32_t status;
1116 	int r = 0;
1117 
1118 	status = bus_space_read_4(t, seb, GEM_STATUS);
1119 	DPRINTF(sc, ("%s: gem_intr: cplt %xstatus %b\n",
1120 		sc->sc_dev.dv_xname, (status>>19), status, GEM_INTR_BITS));
1121 
1122 	if (status == 0xffffffff)
1123 		return (0);
1124 
1125 	if ((status & GEM_INTR_PCS) != 0)
1126 		r |= gem_pint(sc);
1127 
1128 	if ((status & (GEM_INTR_RX_TAG_ERR | GEM_INTR_BERR)) != 0)
1129 		r |= gem_eint(sc, status);
1130 
1131 	if ((status & (GEM_INTR_TX_EMPTY | GEM_INTR_TX_INTME)) != 0)
1132 		r |= gem_tint(sc, status);
1133 
1134 	if ((status & (GEM_INTR_RX_DONE | GEM_INTR_RX_NOBUF)) != 0)
1135 		r |= gem_rint(sc);
1136 
1137 	/* We should eventually do more than just print out error stats. */
1138 	if (status & GEM_INTR_TX_MAC) {
1139 		int txstat = bus_space_read_4(t, seb, GEM_MAC_TX_STATUS);
1140 #ifdef GEM_DEBUG
1141 		if (txstat & ~GEM_MAC_TX_XMIT_DONE)
1142 			printf("%s: MAC tx fault, status %x\n",
1143 			    sc->sc_dev.dv_xname, txstat);
1144 #endif
1145 		if (txstat & (GEM_MAC_TX_UNDERRUN | GEM_MAC_TX_PKT_TOO_LONG))
1146 			gem_init(ifp);
1147 	}
1148 	if (status & GEM_INTR_RX_MAC) {
1149 		int rxstat = bus_space_read_4(t, seb, GEM_MAC_RX_STATUS);
1150 #ifdef GEM_DEBUG
1151  		if (rxstat & ~GEM_MAC_RX_DONE)
1152  			printf("%s: MAC rx fault, status %x\n",
1153  			    sc->sc_dev.dv_xname, rxstat);
1154 #endif
1155 		if (rxstat & GEM_MAC_RX_OVERFLOW) {
1156 			ifp->if_ierrors++;
1157 
1158 			/*
1159 			 * Apparently a silicon bug causes ERI to hang
1160 			 * from time to time.  So if we detect an RX
1161 			 * FIFO overflow, we fire off a timer, and
1162 			 * check whether we're still making progress
1163 			 * by looking at the RX FIFO write and read
1164 			 * pointers.
1165 			 */
1166 			sc->sc_rx_fifo_wr_ptr =
1167 				bus_space_read_4(t, seb, GEM_RX_FIFO_WR_PTR);
1168 			sc->sc_rx_fifo_rd_ptr =
1169 				bus_space_read_4(t, seb, GEM_RX_FIFO_RD_PTR);
1170 			timeout_add_msec(&sc->sc_rx_watchdog, 400);
1171 		}
1172 #ifdef GEM_DEBUG
1173 		else if (rxstat & ~(GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT))
1174 			printf("%s: MAC rx fault, status %x\n",
1175 			    sc->sc_dev.dv_xname, rxstat);
1176 #endif
1177 	}
1178 	return (r);
1179 }
1180 
1181 void
1182 gem_rx_watchdog(void *arg)
1183 {
1184 	struct gem_softc *sc = arg;
1185 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
1186 	bus_space_tag_t t = sc->sc_bustag;
1187 	bus_space_handle_t h = sc->sc_h1;
1188 	u_int32_t rx_fifo_wr_ptr;
1189 	u_int32_t rx_fifo_rd_ptr;
1190 	u_int32_t state;
1191 
1192 	if ((ifp->if_flags & IFF_RUNNING) == 0)
1193 		return;
1194 
1195 	rx_fifo_wr_ptr = bus_space_read_4(t, h, GEM_RX_FIFO_WR_PTR);
1196 	rx_fifo_rd_ptr = bus_space_read_4(t, h, GEM_RX_FIFO_RD_PTR);
1197 	state = bus_space_read_4(t, h, GEM_MAC_MAC_STATE);
1198 	if ((state & GEM_MAC_STATE_OVERFLOW) == GEM_MAC_STATE_OVERFLOW &&
1199 	    ((rx_fifo_wr_ptr == rx_fifo_rd_ptr) ||
1200 	     ((sc->sc_rx_fifo_wr_ptr == rx_fifo_wr_ptr) &&
1201 	      (sc->sc_rx_fifo_rd_ptr == rx_fifo_rd_ptr)))) {
1202 		/*
1203 		 * The RX state machine is still in overflow state and
1204 		 * the RX FIFO write and read pointers seem to be
1205 		 * stuck.  Whack the chip over the head to get things
1206 		 * going again.
1207 		 */
1208 		gem_init(ifp);
1209 	}
1210 }
1211 
1212 void
1213 gem_watchdog(struct ifnet *ifp)
1214 {
1215 	struct gem_softc *sc = ifp->if_softc;
1216 
1217 	DPRINTF(sc, ("gem_watchdog: GEM_RX_CONFIG %x GEM_MAC_RX_STATUS %x "
1218 		"GEM_MAC_RX_CONFIG %x\n",
1219 		bus_space_read_4(sc->sc_bustag, sc->sc_h1, GEM_RX_CONFIG),
1220 		bus_space_read_4(sc->sc_bustag, sc->sc_h1, GEM_MAC_RX_STATUS),
1221 		bus_space_read_4(sc->sc_bustag, sc->sc_h1, GEM_MAC_RX_CONFIG)));
1222 
1223 	log(LOG_ERR, "%s: device timeout\n", sc->sc_dev.dv_xname);
1224 	++ifp->if_oerrors;
1225 
1226 	/* Try to get more packets going. */
1227 	gem_init(ifp);
1228 }
1229 
1230 /*
1231  * Initialize the MII Management Interface
1232  */
1233 void
1234 gem_mifinit(struct gem_softc *sc)
1235 {
1236 	bus_space_tag_t t = sc->sc_bustag;
1237 	bus_space_handle_t mif = sc->sc_h1;
1238 
1239 	/* Configure the MIF in frame mode */
1240 	sc->sc_mif_config = bus_space_read_4(t, mif, GEM_MIF_CONFIG);
1241 	sc->sc_mif_config &= ~GEM_MIF_CONFIG_BB_ENA;
1242 	bus_space_write_4(t, mif, GEM_MIF_CONFIG, sc->sc_mif_config);
1243 }
1244 
1245 /*
1246  * MII interface
1247  *
1248  * The GEM MII interface supports at least three different operating modes:
1249  *
1250  * Bitbang mode is implemented using data, clock and output enable registers.
1251  *
1252  * Frame mode is implemented by loading a complete frame into the frame
1253  * register and polling the valid bit for completion.
1254  *
1255  * Polling mode uses the frame register but completion is indicated by
1256  * an interrupt.
1257  *
1258  */
1259 int
1260 gem_mii_readreg(struct device *self, int phy, int reg)
1261 {
1262 	struct gem_softc *sc = (void *)self;
1263 	bus_space_tag_t t = sc->sc_bustag;
1264 	bus_space_handle_t mif = sc->sc_h1;
1265 	int n;
1266 	u_int32_t v;
1267 
1268 #ifdef GEM_DEBUG
1269 	if (sc->sc_debug)
1270 		printf("gem_mii_readreg: phy %d reg %d\n", phy, reg);
1271 #endif
1272 
1273 	/* Construct the frame command */
1274 	v = (reg << GEM_MIF_REG_SHIFT)	| (phy << GEM_MIF_PHY_SHIFT) |
1275 		GEM_MIF_FRAME_READ;
1276 
1277 	bus_space_write_4(t, mif, GEM_MIF_FRAME, v);
1278 	for (n = 0; n < 100; n++) {
1279 		DELAY(1);
1280 		v = bus_space_read_4(t, mif, GEM_MIF_FRAME);
1281 		if (v & GEM_MIF_FRAME_TA0)
1282 			return (v & GEM_MIF_FRAME_DATA);
1283 	}
1284 
1285 	printf("%s: mii_read timeout\n", sc->sc_dev.dv_xname);
1286 	return (0);
1287 }
1288 
1289 void
1290 gem_mii_writereg(struct device *self, int phy, int reg, int val)
1291 {
1292 	struct gem_softc *sc = (void *)self;
1293 	bus_space_tag_t t = sc->sc_bustag;
1294 	bus_space_handle_t mif = sc->sc_h1;
1295 	int n;
1296 	u_int32_t v;
1297 
1298 #ifdef GEM_DEBUG
1299 	if (sc->sc_debug)
1300 		printf("gem_mii_writereg: phy %d reg %d val %x\n",
1301 			phy, reg, val);
1302 #endif
1303 
1304 	/* Construct the frame command */
1305 	v = GEM_MIF_FRAME_WRITE			|
1306 	    (phy << GEM_MIF_PHY_SHIFT)		|
1307 	    (reg << GEM_MIF_REG_SHIFT)		|
1308 	    (val & GEM_MIF_FRAME_DATA);
1309 
1310 	bus_space_write_4(t, mif, GEM_MIF_FRAME, v);
1311 	for (n = 0; n < 100; n++) {
1312 		DELAY(1);
1313 		v = bus_space_read_4(t, mif, GEM_MIF_FRAME);
1314 		if (v & GEM_MIF_FRAME_TA0)
1315 			return;
1316 	}
1317 
1318 	printf("%s: mii_write timeout\n", sc->sc_dev.dv_xname);
1319 }
1320 
1321 void
1322 gem_mii_statchg(struct device *dev)
1323 {
1324 	struct gem_softc *sc = (void *)dev;
1325 #ifdef GEM_DEBUG
1326 	int instance = IFM_INST(sc->sc_mii.mii_media.ifm_cur->ifm_media);
1327 #endif
1328 	bus_space_tag_t t = sc->sc_bustag;
1329 	bus_space_handle_t mac = sc->sc_h1;
1330 	u_int32_t v;
1331 
1332 #ifdef GEM_DEBUG
1333 	if (sc->sc_debug)
1334 		printf("gem_mii_statchg: status change: phy = %d\n", instance);
1335 #endif
1336 
1337 	/* Set tx full duplex options */
1338 	bus_space_write_4(t, mac, GEM_MAC_TX_CONFIG, 0);
1339 	delay(10000); /* reg must be cleared and delay before changing. */
1340 	v = GEM_MAC_TX_ENA_IPG0|GEM_MAC_TX_NGU|GEM_MAC_TX_NGU_LIMIT|
1341 		GEM_MAC_TX_ENABLE;
1342 	if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_FDX) != 0) {
1343 		v |= GEM_MAC_TX_IGN_CARRIER|GEM_MAC_TX_IGN_COLLIS;
1344 	}
1345 	bus_space_write_4(t, mac, GEM_MAC_TX_CONFIG, v);
1346 
1347 	/* XIF Configuration */
1348 	v = GEM_MAC_XIF_TX_MII_ENA;
1349 	v |= GEM_MAC_XIF_LINK_LED;
1350 
1351 	/* External MII needs echo disable if half duplex. */
1352 	if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_FDX) != 0)
1353 		/* turn on full duplex LED */
1354 		v |= GEM_MAC_XIF_FDPLX_LED;
1355 	else
1356 		/* half duplex -- disable echo */
1357 		v |= GEM_MAC_XIF_ECHO_DISABL;
1358 
1359 	switch (IFM_SUBTYPE(sc->sc_mii.mii_media_active)) {
1360 	case IFM_1000_T:  /* Gigabit using GMII interface */
1361 	case IFM_1000_SX:
1362 		v |= GEM_MAC_XIF_GMII_MODE;
1363 		break;
1364 	default:
1365 		v &= ~GEM_MAC_XIF_GMII_MODE;
1366 	}
1367 	bus_space_write_4(t, mac, GEM_MAC_XIF_CONFIG, v);
1368 
1369 	/*
1370 	 * 802.3x flow control
1371 	 */
1372 	v = bus_space_read_4(t, mac, GEM_MAC_CONTROL_CONFIG);
1373 	v &= ~(GEM_MAC_CC_RX_PAUSE | GEM_MAC_CC_TX_PAUSE);
1374 	if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_ETH_RXPAUSE) != 0)
1375 		v |= GEM_MAC_CC_RX_PAUSE;
1376 	if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_ETH_TXPAUSE) != 0)
1377 		v |= GEM_MAC_CC_TX_PAUSE;
1378 	bus_space_write_4(t, mac, GEM_MAC_CONTROL_CONFIG, v);
1379 }
1380 
1381 int
1382 gem_pcs_readreg(struct device *self, int phy, int reg)
1383 {
1384 	struct gem_softc *sc = (void *)self;
1385 	bus_space_tag_t t = sc->sc_bustag;
1386 	bus_space_handle_t pcs = sc->sc_h1;
1387 
1388 #ifdef GEM_DEBUG
1389 	if (sc->sc_debug)
1390 		printf("gem_pcs_readreg: phy %d reg %d\n", phy, reg);
1391 #endif
1392 
1393 	if (phy != GEM_PHYAD_EXTERNAL)
1394 		return (0);
1395 
1396 	switch (reg) {
1397 	case MII_BMCR:
1398 		reg = GEM_MII_CONTROL;
1399 		break;
1400 	case MII_BMSR:
1401 		reg = GEM_MII_STATUS;
1402 		break;
1403 	case MII_ANAR:
1404 		reg = GEM_MII_ANAR;
1405 		break;
1406 	case MII_ANLPAR:
1407 		reg = GEM_MII_ANLPAR;
1408 		break;
1409 	case MII_EXTSR:
1410 		return (EXTSR_1000XFDX|EXTSR_1000XHDX);
1411 	default:
1412 		return (0);
1413 	}
1414 
1415 	return bus_space_read_4(t, pcs, reg);
1416 }
1417 
1418 void
1419 gem_pcs_writereg(struct device *self, int phy, int reg, int val)
1420 {
1421 	struct gem_softc *sc = (void *)self;
1422 	bus_space_tag_t t = sc->sc_bustag;
1423 	bus_space_handle_t pcs = sc->sc_h1;
1424 	int reset = 0;
1425 
1426 #ifdef GEM_DEBUG
1427 	if (sc->sc_debug)
1428 		printf("gem_pcs_writereg: phy %d reg %d val %x\n",
1429 			phy, reg, val);
1430 #endif
1431 
1432 	if (phy != GEM_PHYAD_EXTERNAL)
1433 		return;
1434 
1435 	if (reg == MII_ANAR)
1436 		bus_space_write_4(t, pcs, GEM_MII_CONFIG, 0);
1437 
1438 	switch (reg) {
1439 	case MII_BMCR:
1440 		reset = (val & GEM_MII_CONTROL_RESET);
1441 		reg = GEM_MII_CONTROL;
1442 		break;
1443 	case MII_BMSR:
1444 		reg = GEM_MII_STATUS;
1445 		break;
1446 	case MII_ANAR:
1447 		reg = GEM_MII_ANAR;
1448 		break;
1449 	case MII_ANLPAR:
1450 		reg = GEM_MII_ANLPAR;
1451 		break;
1452 	default:
1453 		return;
1454 	}
1455 
1456 	bus_space_write_4(t, pcs, reg, val);
1457 
1458 	if (reset)
1459 		gem_bitwait(sc, pcs, GEM_MII_CONTROL, GEM_MII_CONTROL_RESET, 0);
1460 
1461 	if (reg == GEM_MII_ANAR || reset) {
1462 		bus_space_write_4(t, pcs, GEM_MII_SLINK_CONTROL,
1463 		    GEM_MII_SLINK_LOOPBACK|GEM_MII_SLINK_EN_SYNC_D);
1464 		bus_space_write_4(t, pcs, GEM_MII_CONFIG,
1465 		    GEM_MII_CONFIG_ENABLE);
1466 	}
1467 }
1468 
1469 int
1470 gem_mediachange(struct ifnet *ifp)
1471 {
1472 	struct gem_softc *sc = ifp->if_softc;
1473 	struct mii_data *mii = &sc->sc_mii;
1474 
1475 	if (mii->mii_instance) {
1476 		struct mii_softc *miisc;
1477 		LIST_FOREACH(miisc, &mii->mii_phys, mii_list)
1478 			mii_phy_reset(miisc);
1479 	}
1480 
1481 	return (mii_mediachg(&sc->sc_mii));
1482 }
1483 
1484 void
1485 gem_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
1486 {
1487 	struct gem_softc *sc = ifp->if_softc;
1488 
1489 	mii_pollstat(&sc->sc_mii);
1490 	ifmr->ifm_active = sc->sc_mii.mii_media_active;
1491 	ifmr->ifm_status = sc->sc_mii.mii_media_status;
1492 }
1493 
1494 /*
1495  * Process an ioctl request.
1496  */
1497 int
1498 gem_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1499 {
1500 	struct gem_softc *sc = ifp->if_softc;
1501 	struct ifaddr *ifa = (struct ifaddr *)data;
1502 	struct ifreq *ifr = (struct ifreq *)data;
1503 	int s, error = 0;
1504 
1505 	s = splnet();
1506 
1507 	switch (cmd) {
1508 	case SIOCSIFADDR:
1509 		ifp->if_flags |= IFF_UP;
1510 		if ((ifp->if_flags & IFF_RUNNING) == 0)
1511 			gem_init(ifp);
1512 #ifdef INET
1513 		if (ifa->ifa_addr->sa_family == AF_INET)
1514 			arp_ifinit(&sc->sc_arpcom, ifa);
1515 #endif
1516 		break;
1517 
1518 	case SIOCSIFFLAGS:
1519 		if (ifp->if_flags & IFF_UP) {
1520 			if (ifp->if_flags & IFF_RUNNING)
1521 				error = ENETRESET;
1522 			else
1523 				gem_init(ifp);
1524 		} else {
1525 			if (ifp->if_flags & IFF_RUNNING)
1526 				gem_stop(ifp, 0);
1527 		}
1528 #ifdef GEM_DEBUG
1529 		sc->sc_debug = (ifp->if_flags & IFF_DEBUG) != 0 ? 1 : 0;
1530 #endif
1531 		break;
1532 
1533 	case SIOCGIFMEDIA:
1534 	case SIOCSIFMEDIA:
1535 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd);
1536 		break;
1537 
1538 	case SIOCGIFRXR:
1539 		error = if_rxr_ioctl((struct if_rxrinfo *)ifr->ifr_data,
1540 		    NULL, MCLBYTES, &sc->sc_rx_ring);
1541 		break;
1542 
1543 	default:
1544 		error = ether_ioctl(ifp, &sc->sc_arpcom, cmd, data);
1545 	}
1546 
1547 	if (error == ENETRESET) {
1548 		if (ifp->if_flags & IFF_RUNNING)
1549 			gem_iff(sc);
1550 		error = 0;
1551 	}
1552 
1553 	splx(s);
1554 	return (error);
1555 }
1556 
1557 void
1558 gem_iff(struct gem_softc *sc)
1559 {
1560 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
1561 	struct arpcom *ac = &sc->sc_arpcom;
1562 	struct ether_multi *enm;
1563 	struct ether_multistep step;
1564 	bus_space_tag_t t = sc->sc_bustag;
1565 	bus_space_handle_t h = sc->sc_h1;
1566 	u_int32_t crc, hash[16], rxcfg;
1567 	int i;
1568 
1569 	rxcfg = bus_space_read_4(t, h, GEM_MAC_RX_CONFIG);
1570 	rxcfg &= ~(GEM_MAC_RX_HASH_FILTER | GEM_MAC_RX_PROMISCUOUS |
1571 	    GEM_MAC_RX_PROMISC_GRP);
1572 	ifp->if_flags &= ~IFF_ALLMULTI;
1573 
1574 	if (ifp->if_flags & IFF_PROMISC || ac->ac_multirangecnt > 0) {
1575 		ifp->if_flags |= IFF_ALLMULTI;
1576 		if (ifp->if_flags & IFF_PROMISC)
1577 			rxcfg |= GEM_MAC_RX_PROMISCUOUS;
1578 		else
1579 			rxcfg |= GEM_MAC_RX_PROMISC_GRP;
1580 	} else {
1581 		/*
1582 		 * Set up multicast address filter by passing all multicast
1583 		 * addresses through a crc generator, and then using the
1584 		 * high order 8 bits as an index into the 256 bit logical
1585 		 * address filter.  The high order 4 bits selects the word,
1586 		 * while the other 4 bits select the bit within the word
1587 		 * (where bit 0 is the MSB).
1588 		 */
1589 
1590 		rxcfg |= GEM_MAC_RX_HASH_FILTER;
1591 
1592 		/* Clear hash table */
1593 		for (i = 0; i < 16; i++)
1594 			hash[i] = 0;
1595 
1596 		ETHER_FIRST_MULTI(step, ac, enm);
1597 		while (enm != NULL) {
1598 			crc = ether_crc32_le(enm->enm_addrlo,
1599 			    ETHER_ADDR_LEN);
1600 
1601 			/* Just want the 8 most significant bits. */
1602 			crc >>= 24;
1603 
1604 			/* Set the corresponding bit in the filter. */
1605 			hash[crc >> 4] |= 1 << (15 - (crc & 15));
1606 
1607 			ETHER_NEXT_MULTI(step, enm);
1608 		}
1609 
1610 		/* Now load the hash table into the chip (if we are using it) */
1611 		for (i = 0; i < 16; i++) {
1612 			bus_space_write_4(t, h,
1613 			    GEM_MAC_HASH0 + i * (GEM_MAC_HASH1 - GEM_MAC_HASH0),
1614 			    hash[i]);
1615 		}
1616 	}
1617 
1618 	bus_space_write_4(t, h, GEM_MAC_RX_CONFIG, rxcfg);
1619 }
1620 
1621 /*
1622  * Transmit interrupt.
1623  */
1624 int
1625 gem_tint(struct gem_softc *sc, u_int32_t status)
1626 {
1627 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
1628 	struct gem_sxd *sd;
1629 	u_int32_t cons, hwcons;
1630 
1631 	hwcons = status >> 19;
1632 	cons = sc->sc_tx_cons;
1633 	while (cons != hwcons) {
1634 		sd = &sc->sc_txd[cons];
1635 		if (sd->sd_mbuf != NULL) {
1636 			bus_dmamap_sync(sc->sc_dmatag, sd->sd_map, 0,
1637 			    sd->sd_map->dm_mapsize, BUS_DMASYNC_POSTWRITE);
1638 			bus_dmamap_unload(sc->sc_dmatag, sd->sd_map);
1639 			m_freem(sd->sd_mbuf);
1640 			sd->sd_mbuf = NULL;
1641 			ifp->if_opackets++;
1642 		}
1643 		sc->sc_tx_cnt--;
1644 		if (++cons == GEM_NTXDESC)
1645 			cons = 0;
1646 	}
1647 	sc->sc_tx_cons = cons;
1648 
1649 	if (sc->sc_tx_cnt < GEM_NTXDESC - 2)
1650 		ifp->if_flags &= ~IFF_OACTIVE;
1651 	if (sc->sc_tx_cnt == 0)
1652 		ifp->if_timer = 0;
1653 
1654 	gem_start(ifp);
1655 
1656 	return (1);
1657 }
1658 
1659 void
1660 gem_start(struct ifnet *ifp)
1661 {
1662 	struct gem_softc *sc = ifp->if_softc;
1663 	struct mbuf *m;
1664 	u_int64_t flags;
1665 	bus_dmamap_t map;
1666 	u_int32_t cur, frag, i;
1667 	int error;
1668 
1669 	if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
1670 		return;
1671 
1672 	while (sc->sc_txd[sc->sc_tx_prod].sd_mbuf == NULL) {
1673 		IFQ_POLL(&ifp->if_snd, m);
1674 		if (m == NULL)
1675 			break;
1676 
1677 		/*
1678 		 * Encapsulate this packet and start it going...
1679 		 * or fail...
1680 		 */
1681 
1682 		cur = frag = sc->sc_tx_prod;
1683 		map = sc->sc_txd[cur].sd_map;
1684 
1685 		error = bus_dmamap_load_mbuf(sc->sc_dmatag, map, m,
1686 		    BUS_DMA_NOWAIT);
1687 		if (error != 0 && error != EFBIG)
1688 			goto drop;
1689 		if (error != 0) {
1690 			/* Too many fragments, linearize. */
1691 			if (m_defrag(m, M_DONTWAIT))
1692 				goto drop;
1693 			error = bus_dmamap_load_mbuf(sc->sc_dmatag, map, m,
1694 			    BUS_DMA_NOWAIT);
1695 			if (error != 0)
1696 				goto drop;
1697 		}
1698 
1699 		if ((sc->sc_tx_cnt + map->dm_nsegs) > (GEM_NTXDESC - 2)) {
1700 			bus_dmamap_unload(sc->sc_dmatag, map);
1701 			ifp->if_flags |= IFF_OACTIVE;
1702 			break;
1703 		}
1704 
1705 		/* We are now committed to transmitting the packet. */
1706 		IFQ_DEQUEUE(&ifp->if_snd, m);
1707 
1708 #if NBPFILTER > 0
1709 		/*
1710 		 * If BPF is listening on this interface, let it see the
1711 		 * packet before we commit it to the wire.
1712 		 */
1713 		if (ifp->if_bpf)
1714 			bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_OUT);
1715 #endif
1716 
1717 		bus_dmamap_sync(sc->sc_dmatag, map, 0, map->dm_mapsize,
1718 		    BUS_DMASYNC_PREWRITE);
1719 
1720 		for (i = 0; i < map->dm_nsegs; i++) {
1721 			GEM_DMA_WRITE(sc, &sc->sc_txdescs[frag].gd_addr,
1722 			    map->dm_segs[i].ds_addr);
1723 			flags = map->dm_segs[i].ds_len & GEM_TD_BUFSIZE;
1724 			if (i == 0)
1725 				flags |= GEM_TD_START_OF_PACKET;
1726 			if (i == (map->dm_nsegs - 1))
1727 				flags |= GEM_TD_END_OF_PACKET;
1728 			GEM_DMA_WRITE(sc, &sc->sc_txdescs[frag].gd_flags,
1729 			    flags);
1730 			bus_dmamap_sync(sc->sc_dmatag, sc->sc_cddmamap,
1731 			    GEM_CDTXOFF(frag), sizeof(struct gem_desc),
1732 			    BUS_DMASYNC_PREWRITE);
1733 			cur = frag;
1734 			if (++frag == GEM_NTXDESC)
1735 				frag = 0;
1736 		}
1737 
1738 		sc->sc_tx_cnt += map->dm_nsegs;
1739 		sc->sc_txd[sc->sc_tx_prod].sd_map = sc->sc_txd[cur].sd_map;
1740 		sc->sc_txd[cur].sd_map = map;
1741 		sc->sc_txd[cur].sd_mbuf = m;
1742 
1743 		bus_space_write_4(sc->sc_bustag, sc->sc_h1, GEM_TX_KICK, frag);
1744 		sc->sc_tx_prod = frag;
1745 
1746 		ifp->if_timer = 5;
1747 	}
1748 
1749 	return;
1750 
1751  drop:
1752 	IFQ_DEQUEUE(&ifp->if_snd, m);
1753 	m_freem(m);
1754 	ifp->if_oerrors++;
1755 }
1756