xref: /openbsd-src/sys/dev/ic/gem.c (revision c7e8ea31cd41a963f06f0a8ba93948b06aa6b4a4)
1 /*	$OpenBSD: gem.c,v 1.122 2017/06/08 01:34:00 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 #include <sys/endian.h>
51 #include <sys/atomic.h>
52 
53 #include <net/if.h>
54 #include <net/if_media.h>
55 
56 #include <netinet/in.h>
57 #include <netinet/if_ether.h>
58 
59 #if NBPFILTER > 0
60 #include <net/bpf.h>
61 #endif
62 
63 #include <machine/bus.h>
64 #include <machine/intr.h>
65 
66 #include <dev/mii/mii.h>
67 #include <dev/mii/miivar.h>
68 
69 #include <dev/ic/gemreg.h>
70 #include <dev/ic/gemvar.h>
71 
72 #define TRIES	10000
73 
74 struct cfdriver gem_cd = {
75 	NULL, "gem", DV_IFNET
76 };
77 
78 void		gem_start(struct ifqueue *);
79 void		gem_stop(struct ifnet *, int);
80 int		gem_ioctl(struct ifnet *, u_long, caddr_t);
81 void		gem_tick(void *);
82 void		gem_watchdog(struct ifnet *);
83 int		gem_init(struct ifnet *);
84 void		gem_init_regs(struct gem_softc *);
85 int		gem_ringsize(int);
86 int		gem_meminit(struct gem_softc *);
87 void		gem_mifinit(struct gem_softc *);
88 int		gem_bitwait(struct gem_softc *, bus_space_handle_t, int,
89 		    u_int32_t, u_int32_t);
90 void		gem_reset(struct gem_softc *);
91 int		gem_reset_rx(struct gem_softc *);
92 int		gem_reset_tx(struct gem_softc *);
93 int		gem_disable_rx(struct gem_softc *);
94 int		gem_disable_tx(struct gem_softc *);
95 void		gem_rx_watchdog(void *);
96 void		gem_rxdrain(struct gem_softc *);
97 void		gem_fill_rx_ring(struct gem_softc *);
98 int		gem_add_rxbuf(struct gem_softc *, int idx);
99 int		gem_load_mbuf(struct gem_softc *, struct gem_sxd *,
100 		    struct mbuf *);
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 = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
221 	ifp->if_xflags = IFXF_MPSAFE;
222 	ifp->if_qstart = 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 
227 	ifp->if_capabilities = IFCAP_VLAN_MTU;
228 
229 	/* Initialize ifmedia structures and MII info */
230 	mii->mii_ifp = ifp;
231 	mii->mii_readreg = gem_mii_readreg;
232 	mii->mii_writereg = gem_mii_writereg;
233 	mii->mii_statchg = gem_mii_statchg;
234 
235 	ifmedia_init(&mii->mii_media, 0, gem_mediachange, gem_mediastatus);
236 
237 	/* Bad things will happen if we touch this register on ERI. */
238 	if (sc->sc_variant != GEM_SUN_ERI)
239 		bus_space_write_4(sc->sc_bustag, sc->sc_h1,
240 		    GEM_MII_DATAPATH_MODE, 0);
241 
242 	gem_mifinit(sc);
243 
244 	mii_flags = MIIF_DOPAUSE;
245 
246 	/*
247 	 * Look for an external PHY.
248 	 */
249 	if (sc->sc_mif_config & GEM_MIF_CONFIG_MDI1) {
250 		sc->sc_mif_config |= GEM_MIF_CONFIG_PHY_SEL;
251 		bus_space_write_4(sc->sc_bustag, sc->sc_h1,
252 	            GEM_MIF_CONFIG, sc->sc_mif_config);
253 
254 		switch (sc->sc_variant) {
255 		case GEM_SUN_ERI:
256 			phyad = GEM_PHYAD_EXTERNAL;
257 			break;
258 		default:
259 			phyad = MII_PHY_ANY;
260 			break;
261 		}
262 
263 		mii_attach(&sc->sc_dev, mii, 0xffffffff, phyad,
264 		    MII_OFFSET_ANY, mii_flags);
265 	}
266 
267 	/*
268 	 * Fall back on an internal PHY if no external PHY was found.
269 	 * Note that with Apple (K2) GMACs GEM_MIF_CONFIG_MDI0 can't be
270 	 * trusted when the firmware has powered down the chip
271 	 */
272 	child = LIST_FIRST(&mii->mii_phys);
273 	if (child == NULL &&
274 	    (sc->sc_mif_config & GEM_MIF_CONFIG_MDI0 || GEM_IS_APPLE(sc))) {
275 		sc->sc_mif_config &= ~GEM_MIF_CONFIG_PHY_SEL;
276 		bus_space_write_4(sc->sc_bustag, sc->sc_h1,
277 	            GEM_MIF_CONFIG, sc->sc_mif_config);
278 
279 		switch (sc->sc_variant) {
280 		case GEM_SUN_ERI:
281 		case GEM_APPLE_K2_GMAC:
282 			phyad = GEM_PHYAD_INTERNAL;
283 			break;
284 		case GEM_APPLE_GMAC:
285 			phyad = GEM_PHYAD_EXTERNAL;
286 			break;
287 		default:
288 			phyad = MII_PHY_ANY;
289 			break;
290 		}
291 
292 		mii_attach(&sc->sc_dev, mii, 0xffffffff, phyad,
293 		    MII_OFFSET_ANY, mii_flags);
294 	}
295 
296 	/*
297 	 * Try the external PCS SERDES if we didn't find any MII
298 	 * devices.
299 	 */
300 	child = LIST_FIRST(&mii->mii_phys);
301 	if (child == NULL && sc->sc_variant != GEM_SUN_ERI) {
302 		bus_space_write_4(sc->sc_bustag, sc->sc_h1,
303 		    GEM_MII_DATAPATH_MODE, GEM_MII_DATAPATH_SERDES);
304 
305 		bus_space_write_4(sc->sc_bustag, sc->sc_h1,
306 		    GEM_MII_SLINK_CONTROL,
307 		    GEM_MII_SLINK_LOOPBACK|GEM_MII_SLINK_EN_SYNC_D);
308 
309 		bus_space_write_4(sc->sc_bustag, sc->sc_h1,
310 		     GEM_MII_CONFIG, GEM_MII_CONFIG_ENABLE);
311 
312 		mii->mii_readreg = gem_pcs_readreg;
313 		mii->mii_writereg = gem_pcs_writereg;
314 
315 		mii_flags |= MIIF_NOISOLATE;
316 
317 		mii_attach(&sc->sc_dev, mii, 0xffffffff, MII_PHY_ANY,
318 		    MII_OFFSET_ANY, mii_flags);
319 	}
320 
321 	child = LIST_FIRST(&mii->mii_phys);
322 	if (child == NULL) {
323 		/* No PHY attached */
324 		ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
325 		ifmedia_set(&sc->sc_media, IFM_ETHER|IFM_MANUAL);
326 	} else {
327 		/*
328 		 * XXX - we can really do the following ONLY if the
329 		 * phy indeed has the auto negotiation capability!!
330 		 */
331 		ifmedia_set(&sc->sc_media, IFM_ETHER|IFM_AUTO);
332 	}
333 
334 	/* Check if we support GigE media. */
335 	TAILQ_FOREACH(ifm, &sc->sc_media.ifm_list, ifm_list) {
336 		if (IFM_SUBTYPE(ifm->ifm_media) == IFM_1000_T ||
337 		    IFM_SUBTYPE(ifm->ifm_media) == IFM_1000_SX ||
338 		    IFM_SUBTYPE(ifm->ifm_media) == IFM_1000_LX ||
339 		    IFM_SUBTYPE(ifm->ifm_media) == IFM_1000_CX) {
340 			sc->sc_flags |= GEM_GIGABIT;
341 			break;
342 		}
343 	}
344 
345 	/* Attach the interface. */
346 	if_attach(ifp);
347 	ether_ifattach(ifp);
348 
349 	timeout_set(&sc->sc_tick_ch, gem_tick, sc);
350 	timeout_set(&sc->sc_rx_watchdog, gem_rx_watchdog, sc);
351 	return;
352 
353 	/*
354 	 * Free any resources we've allocated during the failed attach
355 	 * attempt.  Do this in reverse order and fall through.
356 	 */
357  fail_6:
358 	for (i = 0; i < GEM_NTXDESC; i++) {
359 		if (sc->sc_txd[i].sd_map != NULL)
360 			bus_dmamap_destroy(sc->sc_dmatag,
361 			    sc->sc_txd[i].sd_map);
362 	}
363  fail_5:
364 	for (i = 0; i < GEM_NRXDESC; i++) {
365 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
366 			bus_dmamap_destroy(sc->sc_dmatag,
367 			    sc->sc_rxsoft[i].rxs_dmamap);
368 	}
369 	bus_dmamap_unload(sc->sc_dmatag, sc->sc_cddmamap);
370  fail_3:
371 	bus_dmamap_destroy(sc->sc_dmatag, sc->sc_cddmamap);
372  fail_2:
373 	bus_dmamem_unmap(sc->sc_dmatag, (caddr_t)sc->sc_control_data,
374 	    sizeof(struct gem_control_data));
375  fail_1:
376 	bus_dmamem_free(sc->sc_dmatag, &sc->sc_cdseg, sc->sc_cdnseg);
377  fail_0:
378 	return;
379 }
380 
381 void
382 gem_unconfig(struct gem_softc *sc)
383 {
384 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
385 	int i;
386 
387 	gem_stop(ifp, 1);
388 
389 	for (i = 0; i < GEM_NTXDESC; i++) {
390 		if (sc->sc_txd[i].sd_map != NULL)
391 			bus_dmamap_destroy(sc->sc_dmatag,
392 			    sc->sc_txd[i].sd_map);
393 	}
394 	for (i = 0; i < GEM_NRXDESC; i++) {
395 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
396 			bus_dmamap_destroy(sc->sc_dmatag,
397 			    sc->sc_rxsoft[i].rxs_dmamap);
398 	}
399 	bus_dmamap_unload(sc->sc_dmatag, sc->sc_cddmamap);
400 	bus_dmamap_destroy(sc->sc_dmatag, sc->sc_cddmamap);
401 	bus_dmamem_unmap(sc->sc_dmatag, (caddr_t)sc->sc_control_data,
402 	    sizeof(struct gem_control_data));
403 	bus_dmamem_free(sc->sc_dmatag, &sc->sc_cdseg, sc->sc_cdnseg);
404 
405 	/* Detach all PHYs */
406 	mii_detach(&sc->sc_mii, MII_PHY_ANY, MII_OFFSET_ANY);
407 
408 	/* Delete all remaining media. */
409 	ifmedia_delete_instance(&sc->sc_mii.mii_media, IFM_INST_ANY);
410 
411 	ether_ifdetach(ifp);
412 	if_detach(ifp);
413 }
414 
415 
416 void
417 gem_tick(void *arg)
418 {
419 	struct gem_softc *sc = arg;
420 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
421 	bus_space_tag_t t = sc->sc_bustag;
422 	bus_space_handle_t mac = sc->sc_h1;
423 	int s;
424 	u_int32_t v;
425 
426 	/* unload collisions counters */
427 	v = bus_space_read_4(t, mac, GEM_MAC_EXCESS_COLL_CNT) +
428 	    bus_space_read_4(t, mac, GEM_MAC_LATE_COLL_CNT);
429 	ifp->if_collisions += v +
430 	    bus_space_read_4(t, mac, GEM_MAC_NORM_COLL_CNT) +
431 	    bus_space_read_4(t, mac, GEM_MAC_FIRST_COLL_CNT);
432 	ifp->if_oerrors += v;
433 
434 	/* read error counters */
435 	ifp->if_ierrors +=
436 	    bus_space_read_4(t, mac, GEM_MAC_RX_LEN_ERR_CNT) +
437 	    bus_space_read_4(t, mac, GEM_MAC_RX_ALIGN_ERR) +
438 	    bus_space_read_4(t, mac, GEM_MAC_RX_CRC_ERR_CNT) +
439 	    bus_space_read_4(t, mac, GEM_MAC_RX_CODE_VIOL);
440 
441 	/* clear the hardware counters */
442 	bus_space_write_4(t, mac, GEM_MAC_NORM_COLL_CNT, 0);
443 	bus_space_write_4(t, mac, GEM_MAC_FIRST_COLL_CNT, 0);
444 	bus_space_write_4(t, mac, GEM_MAC_EXCESS_COLL_CNT, 0);
445 	bus_space_write_4(t, mac, GEM_MAC_LATE_COLL_CNT, 0);
446 	bus_space_write_4(t, mac, GEM_MAC_RX_LEN_ERR_CNT, 0);
447 	bus_space_write_4(t, mac, GEM_MAC_RX_ALIGN_ERR, 0);
448 	bus_space_write_4(t, mac, GEM_MAC_RX_CRC_ERR_CNT, 0);
449 	bus_space_write_4(t, mac, GEM_MAC_RX_CODE_VIOL, 0);
450 
451 	s = splnet();
452 	mii_tick(&sc->sc_mii);
453 	splx(s);
454 
455 	timeout_add_sec(&sc->sc_tick_ch, 1);
456 }
457 
458 int
459 gem_bitwait(struct gem_softc *sc, bus_space_handle_t h, int r,
460    u_int32_t clr, u_int32_t set)
461 {
462 	int i;
463 	u_int32_t reg;
464 
465 	for (i = TRIES; i--; DELAY(100)) {
466 		reg = bus_space_read_4(sc->sc_bustag, h, r);
467 		if ((reg & clr) == 0 && (reg & set) == set)
468 			return (1);
469 	}
470 
471 	return (0);
472 }
473 
474 void
475 gem_reset(struct gem_softc *sc)
476 {
477 	bus_space_tag_t t = sc->sc_bustag;
478 	bus_space_handle_t h = sc->sc_h2;
479 	int s;
480 
481 	s = splnet();
482 	DPRINTF(sc, ("%s: gem_reset\n", sc->sc_dev.dv_xname));
483 	gem_reset_rx(sc);
484 	gem_reset_tx(sc);
485 
486 	/* Do a full reset */
487 	bus_space_write_4(t, h, GEM_RESET, GEM_RESET_RX|GEM_RESET_TX);
488 	if (!gem_bitwait(sc, h, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX, 0))
489 		printf("%s: cannot reset device\n", sc->sc_dev.dv_xname);
490 	splx(s);
491 }
492 
493 
494 /*
495  * Drain the receive queue.
496  */
497 void
498 gem_rxdrain(struct gem_softc *sc)
499 {
500 	struct gem_rxsoft *rxs;
501 	int i;
502 
503 	for (i = 0; i < GEM_NRXDESC; i++) {
504 		rxs = &sc->sc_rxsoft[i];
505 		if (rxs->rxs_mbuf != NULL) {
506 			bus_dmamap_sync(sc->sc_dmatag, rxs->rxs_dmamap, 0,
507 			    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);
508 			bus_dmamap_unload(sc->sc_dmatag, rxs->rxs_dmamap);
509 			m_freem(rxs->rxs_mbuf);
510 			rxs->rxs_mbuf = NULL;
511 		}
512 	}
513 	sc->sc_rx_prod = sc->sc_rx_cons = 0;
514 }
515 
516 /*
517  * Reset the whole thing.
518  */
519 void
520 gem_stop(struct ifnet *ifp, int softonly)
521 {
522 	struct gem_softc *sc = (struct gem_softc *)ifp->if_softc;
523 	struct gem_sxd *sd;
524 	u_int32_t i;
525 
526 	DPRINTF(sc, ("%s: gem_stop\n", sc->sc_dev.dv_xname));
527 
528 	timeout_del(&sc->sc_tick_ch);
529 
530 	/*
531 	 * Mark the interface down and cancel the watchdog timer.
532 	 */
533 	ifp->if_flags &= ~IFF_RUNNING;
534 	ifq_clr_oactive(&ifp->if_snd);
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 	intr_barrier(sc->sc_ih);
545 	ifq_barrier(&ifp->if_snd);
546 
547 	KASSERT((ifp->if_flags & IFF_RUNNING) == 0);
548 
549 	/*
550 	 * Release any queued transmit buffers.
551 	 */
552 	for (i = 0; i < GEM_NTXDESC; i++) {
553 		sd = &sc->sc_txd[i];
554 		if (sd->sd_mbuf != NULL) {
555 			bus_dmamap_sync(sc->sc_dmatag, sd->sd_map, 0,
556 			    sd->sd_map->dm_mapsize, BUS_DMASYNC_POSTWRITE);
557 			bus_dmamap_unload(sc->sc_dmatag, sd->sd_map);
558 			m_freem(sd->sd_mbuf);
559 			sd->sd_mbuf = NULL;
560 		}
561 	}
562 	sc->sc_tx_cnt = sc->sc_tx_prod = sc->sc_tx_cons = 0;
563 
564 	gem_rxdrain(sc);
565 }
566 
567 
568 /*
569  * Reset the receiver
570  */
571 int
572 gem_reset_rx(struct gem_softc *sc)
573 {
574 	bus_space_tag_t t = sc->sc_bustag;
575 	bus_space_handle_t h = sc->sc_h1, h2 = sc->sc_h2;
576 
577 	/*
578 	 * Resetting while DMA is in progress can cause a bus hang, so we
579 	 * disable DMA first.
580 	 */
581 	gem_disable_rx(sc);
582 	bus_space_write_4(t, h, GEM_RX_CONFIG, 0);
583 	/* Wait till it finishes */
584 	if (!gem_bitwait(sc, h, GEM_RX_CONFIG, 1, 0))
585 		printf("%s: cannot disable rx dma\n", sc->sc_dev.dv_xname);
586 	/* Wait 5ms extra. */
587 	delay(5000);
588 
589 	/* Finally, reset the ERX */
590 	bus_space_write_4(t, h2, GEM_RESET, GEM_RESET_RX);
591 	/* Wait till it finishes */
592 	if (!gem_bitwait(sc, h2, GEM_RESET, GEM_RESET_RX, 0)) {
593 		printf("%s: cannot reset receiver\n", sc->sc_dev.dv_xname);
594 		return (1);
595 	}
596 	return (0);
597 }
598 
599 
600 /*
601  * Reset the transmitter
602  */
603 int
604 gem_reset_tx(struct gem_softc *sc)
605 {
606 	bus_space_tag_t t = sc->sc_bustag;
607 	bus_space_handle_t h = sc->sc_h1, h2 = sc->sc_h2;
608 
609 	/*
610 	 * Resetting while DMA is in progress can cause a bus hang, so we
611 	 * disable DMA first.
612 	 */
613 	gem_disable_tx(sc);
614 	bus_space_write_4(t, h, GEM_TX_CONFIG, 0);
615 	/* Wait till it finishes */
616 	if (!gem_bitwait(sc, h, GEM_TX_CONFIG, 1, 0))
617 		printf("%s: cannot disable tx dma\n", sc->sc_dev.dv_xname);
618 	/* Wait 5ms extra. */
619 	delay(5000);
620 
621 	/* Finally, reset the ETX */
622 	bus_space_write_4(t, h2, GEM_RESET, GEM_RESET_TX);
623 	/* Wait till it finishes */
624 	if (!gem_bitwait(sc, h2, GEM_RESET, GEM_RESET_TX, 0)) {
625 		printf("%s: cannot reset transmitter\n",
626 			sc->sc_dev.dv_xname);
627 		return (1);
628 	}
629 	return (0);
630 }
631 
632 /*
633  * Disable receiver.
634  */
635 int
636 gem_disable_rx(struct gem_softc *sc)
637 {
638 	bus_space_tag_t t = sc->sc_bustag;
639 	bus_space_handle_t h = sc->sc_h1;
640 	u_int32_t cfg;
641 
642 	/* Flip the enable bit */
643 	cfg = bus_space_read_4(t, h, GEM_MAC_RX_CONFIG);
644 	cfg &= ~GEM_MAC_RX_ENABLE;
645 	bus_space_write_4(t, h, GEM_MAC_RX_CONFIG, cfg);
646 
647 	/* Wait for it to finish */
648 	return (gem_bitwait(sc, h, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0));
649 }
650 
651 /*
652  * Disable transmitter.
653  */
654 int
655 gem_disable_tx(struct gem_softc *sc)
656 {
657 	bus_space_tag_t t = sc->sc_bustag;
658 	bus_space_handle_t h = sc->sc_h1;
659 	u_int32_t cfg;
660 
661 	/* Flip the enable bit */
662 	cfg = bus_space_read_4(t, h, GEM_MAC_TX_CONFIG);
663 	cfg &= ~GEM_MAC_TX_ENABLE;
664 	bus_space_write_4(t, h, GEM_MAC_TX_CONFIG, cfg);
665 
666 	/* Wait for it to finish */
667 	return (gem_bitwait(sc, h, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0));
668 }
669 
670 /*
671  * Initialize interface.
672  */
673 int
674 gem_meminit(struct gem_softc *sc)
675 {
676 	int i;
677 
678 	/*
679 	 * Initialize the transmit descriptor ring.
680 	 */
681 	for (i = 0; i < GEM_NTXDESC; i++) {
682 		sc->sc_txdescs[i].gd_flags = 0;
683 		sc->sc_txdescs[i].gd_addr = 0;
684 	}
685 	GEM_CDTXSYNC(sc, 0, GEM_NTXDESC,
686 	    BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
687 
688 	/*
689 	 * Initialize the receive descriptor and receive job
690 	 * descriptor rings.
691 	 */
692 	for (i = 0; i < GEM_NRXDESC; i++) {
693 		sc->sc_rxdescs[i].gd_flags = 0;
694 		sc->sc_rxdescs[i].gd_addr = 0;
695 	}
696 	/* Hardware reads RX descriptors in multiples of four. */
697 	if_rxr_init(&sc->sc_rx_ring, 4, GEM_NRXDESC - 4);
698 	gem_fill_rx_ring(sc);
699 
700 	return (0);
701 }
702 
703 int
704 gem_ringsize(int sz)
705 {
706 	switch (sz) {
707 	case 32:
708 		return GEM_RING_SZ_32;
709 	case 64:
710 		return GEM_RING_SZ_64;
711 	case 128:
712 		return GEM_RING_SZ_128;
713 	case 256:
714 		return GEM_RING_SZ_256;
715 	case 512:
716 		return GEM_RING_SZ_512;
717 	case 1024:
718 		return GEM_RING_SZ_1024;
719 	case 2048:
720 		return GEM_RING_SZ_2048;
721 	case 4096:
722 		return GEM_RING_SZ_4096;
723 	case 8192:
724 		return GEM_RING_SZ_8192;
725 	default:
726 		printf("gem: invalid Receive Descriptor ring size %d\n", sz);
727 		return GEM_RING_SZ_32;
728 	}
729 }
730 
731 /*
732  * Initialization of interface; set up initialization block
733  * and transmit/receive descriptor rings.
734  */
735 int
736 gem_init(struct ifnet *ifp)
737 {
738 
739 	struct gem_softc *sc = (struct gem_softc *)ifp->if_softc;
740 	bus_space_tag_t t = sc->sc_bustag;
741 	bus_space_handle_t h = sc->sc_h1;
742 	int s;
743 	u_int32_t v;
744 
745 	s = splnet();
746 
747 	DPRINTF(sc, ("%s: gem_init: calling stop\n", sc->sc_dev.dv_xname));
748 	/*
749 	 * Initialization sequence. The numbered steps below correspond
750 	 * to the sequence outlined in section 6.3.5.1 in the Ethernet
751 	 * Channel Engine manual (part of the PCIO manual).
752 	 * See also the STP2002-STQ document from Sun Microsystems.
753 	 */
754 
755 	/* step 1 & 2. Reset the Ethernet Channel */
756 	gem_stop(ifp, 0);
757 	gem_reset(sc);
758 	DPRINTF(sc, ("%s: gem_init: restarting\n", sc->sc_dev.dv_xname));
759 
760 	/* Re-initialize the MIF */
761 	gem_mifinit(sc);
762 
763 	/* Call MI reset function if any */
764 	if (sc->sc_hwreset)
765 		(*sc->sc_hwreset)(sc);
766 
767 	/* step 3. Setup data structures in host memory */
768 	gem_meminit(sc);
769 
770 	/* step 4. TX MAC registers & counters */
771 	gem_init_regs(sc);
772 
773 	/* step 5. RX MAC registers & counters */
774 	gem_iff(sc);
775 
776 	/* step 6 & 7. Program Descriptor Ring Base Addresses */
777 	bus_space_write_4(t, h, GEM_TX_RING_PTR_HI,
778 	    (((uint64_t)GEM_CDTXADDR(sc,0)) >> 32));
779 	bus_space_write_4(t, h, GEM_TX_RING_PTR_LO, GEM_CDTXADDR(sc, 0));
780 
781 	bus_space_write_4(t, h, GEM_RX_RING_PTR_HI,
782 	    (((uint64_t)GEM_CDRXADDR(sc,0)) >> 32));
783 	bus_space_write_4(t, h, GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
784 
785 	/* step 8. Global Configuration & Interrupt Mask */
786 	bus_space_write_4(t, h, GEM_INTMASK,
787 		      ~(GEM_INTR_TX_INTME|
788 			GEM_INTR_TX_EMPTY|
789 			GEM_INTR_RX_DONE|GEM_INTR_RX_NOBUF|
790 			GEM_INTR_RX_TAG_ERR|GEM_INTR_PCS|
791 			GEM_INTR_MAC_CONTROL|GEM_INTR_MIF|
792 			GEM_INTR_BERR));
793 	bus_space_write_4(t, h, GEM_MAC_RX_MASK,
794 	    GEM_MAC_RX_DONE|GEM_MAC_RX_FRAME_CNT);
795 	bus_space_write_4(t, h, GEM_MAC_TX_MASK, 0xffff); /* XXXX */
796 	bus_space_write_4(t, h, GEM_MAC_CONTROL_MASK, 0); /* XXXX */
797 
798 	/* step 9. ETX Configuration: use mostly default values */
799 
800 	/* Enable DMA */
801 	v = gem_ringsize(GEM_NTXDESC /*XXX*/);
802 	v |= ((sc->sc_variant == GEM_SUN_ERI ? 0x100 : 0x04ff) << 10) &
803 	    GEM_TX_CONFIG_TXFIFO_TH;
804 	bus_space_write_4(t, h, GEM_TX_CONFIG, v | GEM_TX_CONFIG_TXDMA_EN);
805 	bus_space_write_4(t, h, GEM_TX_KICK, 0);
806 
807 	/* step 10. ERX Configuration */
808 
809 	/* Encode Receive Descriptor ring size: four possible values */
810 	v = gem_ringsize(GEM_NRXDESC /*XXX*/);
811 	/* Enable DMA */
812 	bus_space_write_4(t, h, GEM_RX_CONFIG,
813 		v|(GEM_THRSH_1024<<GEM_RX_CONFIG_FIFO_THRS_SHIFT)|
814 		(2<<GEM_RX_CONFIG_FBOFF_SHFT)|GEM_RX_CONFIG_RXDMA_EN|
815 		(0<<GEM_RX_CONFIG_CXM_START_SHFT));
816 	/*
817 	 * The following value is for an OFF Threshold of about 3/4 full
818 	 * and an ON Threshold of 1/4 full.
819 	 */
820 	bus_space_write_4(t, h, GEM_RX_PAUSE_THRESH,
821 	    (3 * sc->sc_rxfifosize / 256) |
822 	    ((sc->sc_rxfifosize / 256) << 12));
823 	bus_space_write_4(t, h, GEM_RX_BLANKING, (6 << 12) | 6);
824 
825 	/* step 11. Configure Media */
826 	mii_mediachg(&sc->sc_mii);
827 
828 	/* step 12. RX_MAC Configuration Register */
829 	v = bus_space_read_4(t, h, GEM_MAC_RX_CONFIG);
830 	v |= GEM_MAC_RX_ENABLE | GEM_MAC_RX_STRIP_CRC;
831 	bus_space_write_4(t, h, GEM_MAC_RX_CONFIG, v);
832 
833 	/* step 14. Issue Transmit Pending command */
834 
835 	/* Call MI initialization function if any */
836 	if (sc->sc_hwinit)
837 		(*sc->sc_hwinit)(sc);
838 
839 	/* step 15.  Give the receiver a swift kick */
840 	bus_space_write_4(t, h, GEM_RX_KICK, sc->sc_rx_prod);
841 
842 	/* Start the one second timer. */
843 	timeout_add_sec(&sc->sc_tick_ch, 1);
844 
845 	ifp->if_flags |= IFF_RUNNING;
846 	ifq_clr_oactive(&ifp->if_snd);
847 
848 	splx(s);
849 
850 	return (0);
851 }
852 
853 void
854 gem_init_regs(struct gem_softc *sc)
855 {
856 	bus_space_tag_t t = sc->sc_bustag;
857 	bus_space_handle_t h = sc->sc_h1;
858 	u_int32_t v;
859 
860 	/* These regs are not cleared on reset */
861 	sc->sc_inited = 0;
862 	if (!sc->sc_inited) {
863 		/* Load recommended values */
864 		bus_space_write_4(t, h, GEM_MAC_IPG0, 0x00);
865 		bus_space_write_4(t, h, GEM_MAC_IPG1, 0x08);
866 		bus_space_write_4(t, h, GEM_MAC_IPG2, 0x04);
867 
868 		bus_space_write_4(t, h, GEM_MAC_MAC_MIN_FRAME, ETHER_MIN_LEN);
869 		/* Max frame and max burst size */
870 		bus_space_write_4(t, h, GEM_MAC_MAC_MAX_FRAME,
871 		    (ETHER_MAX_LEN + ETHER_VLAN_ENCAP_LEN) | (0x2000 << 16));
872 
873 		bus_space_write_4(t, h, GEM_MAC_PREAMBLE_LEN, 0x07);
874 		bus_space_write_4(t, h, GEM_MAC_JAM_SIZE, 0x04);
875 		bus_space_write_4(t, h, GEM_MAC_ATTEMPT_LIMIT, 0x10);
876 		bus_space_write_4(t, h, GEM_MAC_CONTROL_TYPE, 0x8088);
877 		bus_space_write_4(t, h, GEM_MAC_RANDOM_SEED,
878 		    ((sc->sc_arpcom.ac_enaddr[5]<<8)|sc->sc_arpcom.ac_enaddr[4])&0x3ff);
879 
880 		/* Secondary MAC addr set to 0:0:0:0:0:0 */
881 		bus_space_write_4(t, h, GEM_MAC_ADDR3, 0);
882 		bus_space_write_4(t, h, GEM_MAC_ADDR4, 0);
883 		bus_space_write_4(t, h, GEM_MAC_ADDR5, 0);
884 
885 		/* MAC control addr set to 0:1:c2:0:1:80 */
886 		bus_space_write_4(t, h, GEM_MAC_ADDR6, 0x0001);
887 		bus_space_write_4(t, h, GEM_MAC_ADDR7, 0xc200);
888 		bus_space_write_4(t, h, GEM_MAC_ADDR8, 0x0180);
889 
890 		/* MAC filter addr set to 0:0:0:0:0:0 */
891 		bus_space_write_4(t, h, GEM_MAC_ADDR_FILTER0, 0);
892 		bus_space_write_4(t, h, GEM_MAC_ADDR_FILTER1, 0);
893 		bus_space_write_4(t, h, GEM_MAC_ADDR_FILTER2, 0);
894 
895 		bus_space_write_4(t, h, GEM_MAC_ADR_FLT_MASK1_2, 0);
896 		bus_space_write_4(t, h, GEM_MAC_ADR_FLT_MASK0, 0);
897 
898 		sc->sc_inited = 1;
899 	}
900 
901 	/* Counters need to be zeroed */
902 	bus_space_write_4(t, h, GEM_MAC_NORM_COLL_CNT, 0);
903 	bus_space_write_4(t, h, GEM_MAC_FIRST_COLL_CNT, 0);
904 	bus_space_write_4(t, h, GEM_MAC_EXCESS_COLL_CNT, 0);
905 	bus_space_write_4(t, h, GEM_MAC_LATE_COLL_CNT, 0);
906 	bus_space_write_4(t, h, GEM_MAC_DEFER_TMR_CNT, 0);
907 	bus_space_write_4(t, h, GEM_MAC_PEAK_ATTEMPTS, 0);
908 	bus_space_write_4(t, h, GEM_MAC_RX_FRAME_COUNT, 0);
909 	bus_space_write_4(t, h, GEM_MAC_RX_LEN_ERR_CNT, 0);
910 	bus_space_write_4(t, h, GEM_MAC_RX_ALIGN_ERR, 0);
911 	bus_space_write_4(t, h, GEM_MAC_RX_CRC_ERR_CNT, 0);
912 	bus_space_write_4(t, h, GEM_MAC_RX_CODE_VIOL, 0);
913 
914 	/* Set XOFF PAUSE time */
915 	bus_space_write_4(t, h, GEM_MAC_SEND_PAUSE_CMD, 0x1bf0);
916 
917 	/*
918 	 * Set the internal arbitration to "infinite" bursts of the
919 	 * maximum length of 31 * 64 bytes so DMA transfers aren't
920 	 * split up in cache line size chunks. This greatly improves
921 	 * especially RX performance.
922 	 * Enable silicon bug workarounds for the Apple variants.
923 	 */
924 	v = GEM_CONFIG_TXDMA_LIMIT | GEM_CONFIG_RXDMA_LIMIT;
925 	if (sc->sc_pci)
926 		v |= GEM_CONFIG_BURST_INF;
927 	else
928 		v |= GEM_CONFIG_BURST_64;
929 	if (sc->sc_variant != GEM_SUN_GEM && sc->sc_variant != GEM_SUN_ERI)
930 		v |= GEM_CONFIG_RONPAULBIT | GEM_CONFIG_BUG2FIX;
931 	bus_space_write_4(t, h, GEM_CONFIG, v);
932 
933 	/*
934 	 * Set the station address.
935 	 */
936 	bus_space_write_4(t, h, GEM_MAC_ADDR0,
937 		(sc->sc_arpcom.ac_enaddr[4]<<8) | sc->sc_arpcom.ac_enaddr[5]);
938 	bus_space_write_4(t, h, GEM_MAC_ADDR1,
939 		(sc->sc_arpcom.ac_enaddr[2]<<8) | sc->sc_arpcom.ac_enaddr[3]);
940 	bus_space_write_4(t, h, GEM_MAC_ADDR2,
941 		(sc->sc_arpcom.ac_enaddr[0]<<8) | sc->sc_arpcom.ac_enaddr[1]);
942 }
943 
944 /*
945  * Receive interrupt.
946  */
947 int
948 gem_rint(struct gem_softc *sc)
949 {
950 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
951 	bus_space_tag_t t = sc->sc_bustag;
952 	bus_space_handle_t h = sc->sc_h1;
953 	struct gem_rxsoft *rxs;
954 	struct mbuf_list ml = MBUF_LIST_INITIALIZER();
955 	struct mbuf *m;
956 	u_int64_t rxstat;
957 	int i, len;
958 
959 	if (if_rxr_inuse(&sc->sc_rx_ring) == 0)
960 		return (0);
961 
962 	for (i = sc->sc_rx_cons; if_rxr_inuse(&sc->sc_rx_ring) > 0;
963 	    i = GEM_NEXTRX(i)) {
964 		rxs = &sc->sc_rxsoft[i];
965 
966 		GEM_CDRXSYNC(sc, i,
967 		    BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
968 
969 		rxstat = GEM_DMA_READ(sc, &sc->sc_rxdescs[i].gd_flags);
970 
971 		if (rxstat & GEM_RD_OWN) {
972 			/* We have processed all of the receive buffers. */
973 			break;
974 		}
975 
976 		bus_dmamap_sync(sc->sc_dmatag, rxs->rxs_dmamap, 0,
977 		    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);
978 		bus_dmamap_unload(sc->sc_dmatag, rxs->rxs_dmamap);
979 
980 		m = rxs->rxs_mbuf;
981 		rxs->rxs_mbuf = NULL;
982 
983 		if_rxr_put(&sc->sc_rx_ring, 1);
984 
985 		if (rxstat & GEM_RD_BAD_CRC) {
986 			ifp->if_ierrors++;
987 #ifdef GEM_DEBUG
988 			printf("%s: receive error: CRC error\n",
989 				sc->sc_dev.dv_xname);
990 #endif
991 			m_freem(m);
992 			continue;
993 		}
994 
995 #ifdef GEM_DEBUG
996 		if (ifp->if_flags & IFF_DEBUG) {
997 			printf("    rxsoft %p descriptor %d: ", rxs, i);
998 			printf("gd_flags: 0x%016llx\t", (long long)
999 				GEM_DMA_READ(sc, &sc->sc_rxdescs[i].gd_flags));
1000 			printf("gd_addr: 0x%016llx\n", (long long)
1001 				GEM_DMA_READ(sc, &sc->sc_rxdescs[i].gd_addr));
1002 		}
1003 #endif
1004 
1005 		/* No errors; receive the packet. */
1006 		len = GEM_RD_BUFLEN(rxstat);
1007 
1008 		m->m_data += 2; /* We're already off by two */
1009 		m->m_pkthdr.len = m->m_len = len;
1010 
1011 		ml_enqueue(&ml, 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 	if_input(ifp, &ml);
1023 
1024 	return (1);
1025 }
1026 
1027 void
1028 gem_fill_rx_ring(struct gem_softc *sc)
1029 {
1030 	u_int slots;
1031 
1032 	for (slots = if_rxr_get(&sc->sc_rx_ring, GEM_NRXDESC - 4);
1033 	    slots > 0; slots--) {
1034 		if (gem_add_rxbuf(sc, sc->sc_rx_prod))
1035 			break;
1036 	}
1037 	if_rxr_put(&sc->sc_rx_ring, slots);
1038 }
1039 
1040 /*
1041  * Add a receive buffer to the indicated descriptor.
1042  */
1043 int
1044 gem_add_rxbuf(struct gem_softc *sc, int idx)
1045 {
1046 	struct gem_rxsoft *rxs = &sc->sc_rxsoft[idx];
1047 	struct mbuf *m;
1048 	int error;
1049 
1050 	m = MCLGETI(NULL, M_DONTWAIT, NULL, MCLBYTES);
1051 	if (!m)
1052 		return (ENOBUFS);
1053 	m->m_len = m->m_pkthdr.len = MCLBYTES;
1054 
1055 #ifdef GEM_DEBUG
1056 /* bzero the packet to check dma */
1057 	memset(m->m_ext.ext_buf, 0, m->m_ext.ext_size);
1058 #endif
1059 
1060 	rxs->rxs_mbuf = m;
1061 
1062 	error = bus_dmamap_load_mbuf(sc->sc_dmatag, rxs->rxs_dmamap, m,
1063 	    BUS_DMA_READ|BUS_DMA_NOWAIT);
1064 	if (error) {
1065 		printf("%s: can't load rx DMA map %d, error = %d\n",
1066 		    sc->sc_dev.dv_xname, idx, error);
1067 		panic("gem_add_rxbuf");	/* XXX */
1068 	}
1069 
1070 	bus_dmamap_sync(sc->sc_dmatag, rxs->rxs_dmamap, 0,
1071 	    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_PREREAD);
1072 
1073 	GEM_INIT_RXDESC(sc, idx);
1074 
1075 	sc->sc_rx_prod = GEM_NEXTRX(sc->sc_rx_prod);
1076 
1077 	return (0);
1078 }
1079 
1080 int
1081 gem_eint(struct gem_softc *sc, u_int status)
1082 {
1083 	if ((status & GEM_INTR_MIF) != 0) {
1084 #ifdef GEM_DEBUG
1085 		printf("%s: link status changed\n", sc->sc_dev.dv_xname);
1086 #endif
1087 		return (1);
1088 	}
1089 
1090 	printf("%s: status=%b\n", sc->sc_dev.dv_xname, status, GEM_INTR_BITS);
1091 	return (1);
1092 }
1093 
1094 int
1095 gem_pint(struct gem_softc *sc)
1096 {
1097 	bus_space_tag_t t = sc->sc_bustag;
1098 	bus_space_handle_t seb = sc->sc_h1;
1099 	u_int32_t status;
1100 
1101 	status = bus_space_read_4(t, seb, GEM_MII_INTERRUP_STATUS);
1102 	status |= bus_space_read_4(t, seb, GEM_MII_INTERRUP_STATUS);
1103 #ifdef GEM_DEBUG
1104 	if (status)
1105 		printf("%s: link status changed\n", sc->sc_dev.dv_xname);
1106 #endif
1107 	return (1);
1108 }
1109 
1110 int
1111 gem_intr(void *v)
1112 {
1113 	struct gem_softc *sc = (struct gem_softc *)v;
1114 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
1115 	bus_space_tag_t t = sc->sc_bustag;
1116 	bus_space_handle_t seb = sc->sc_h1;
1117 	u_int32_t status;
1118 	int r = 0;
1119 
1120 	status = bus_space_read_4(t, seb, GEM_STATUS);
1121 	DPRINTF(sc, ("%s: gem_intr: cplt %xstatus %b\n",
1122 		sc->sc_dev.dv_xname, (status>>19), status, GEM_INTR_BITS));
1123 
1124 	if (status == 0xffffffff)
1125 		return (0);
1126 
1127 	if ((status & GEM_INTR_PCS) != 0)
1128 		r |= gem_pint(sc);
1129 
1130 	if ((status & (GEM_INTR_RX_TAG_ERR | GEM_INTR_BERR)) != 0)
1131 		r |= gem_eint(sc, status);
1132 
1133 	if ((status & (GEM_INTR_TX_EMPTY | GEM_INTR_TX_INTME)) != 0)
1134 		r |= gem_tint(sc, status);
1135 
1136 	if ((status & (GEM_INTR_RX_DONE | GEM_INTR_RX_NOBUF)) != 0)
1137 		r |= gem_rint(sc);
1138 
1139 	/* We should eventually do more than just print out error stats. */
1140 	if (status & GEM_INTR_TX_MAC) {
1141 		int txstat = bus_space_read_4(t, seb, GEM_MAC_TX_STATUS);
1142 #ifdef GEM_DEBUG
1143 		if (txstat & ~GEM_MAC_TX_XMIT_DONE)
1144 			printf("%s: MAC tx fault, status %x\n",
1145 			    sc->sc_dev.dv_xname, txstat);
1146 #endif
1147 		if (txstat & (GEM_MAC_TX_UNDERRUN | GEM_MAC_TX_PKT_TOO_LONG)) {
1148 			KERNEL_LOCK();
1149 			gem_init(ifp);
1150 			KERNEL_UNLOCK();
1151 		}
1152 	}
1153 	if (status & GEM_INTR_RX_MAC) {
1154 		int rxstat = bus_space_read_4(t, seb, GEM_MAC_RX_STATUS);
1155 #ifdef GEM_DEBUG
1156  		if (rxstat & ~GEM_MAC_RX_DONE)
1157  			printf("%s: MAC rx fault, status %x\n",
1158  			    sc->sc_dev.dv_xname, rxstat);
1159 #endif
1160 		if (rxstat & GEM_MAC_RX_OVERFLOW) {
1161 			ifp->if_ierrors++;
1162 
1163 			/*
1164 			 * Apparently a silicon bug causes ERI to hang
1165 			 * from time to time.  So if we detect an RX
1166 			 * FIFO overflow, we fire off a timer, and
1167 			 * check whether we're still making progress
1168 			 * by looking at the RX FIFO write and read
1169 			 * pointers.
1170 			 */
1171 			sc->sc_rx_fifo_wr_ptr =
1172 				bus_space_read_4(t, seb, GEM_RX_FIFO_WR_PTR);
1173 			sc->sc_rx_fifo_rd_ptr =
1174 				bus_space_read_4(t, seb, GEM_RX_FIFO_RD_PTR);
1175 			timeout_add_msec(&sc->sc_rx_watchdog, 400);
1176 		}
1177 #ifdef GEM_DEBUG
1178 		else if (rxstat & ~(GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT))
1179 			printf("%s: MAC rx fault, status %x\n",
1180 			    sc->sc_dev.dv_xname, rxstat);
1181 #endif
1182 	}
1183 	return (r);
1184 }
1185 
1186 void
1187 gem_rx_watchdog(void *arg)
1188 {
1189 	struct gem_softc *sc = arg;
1190 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
1191 	bus_space_tag_t t = sc->sc_bustag;
1192 	bus_space_handle_t h = sc->sc_h1;
1193 	u_int32_t rx_fifo_wr_ptr;
1194 	u_int32_t rx_fifo_rd_ptr;
1195 	u_int32_t state;
1196 
1197 	if ((ifp->if_flags & IFF_RUNNING) == 0)
1198 		return;
1199 
1200 	rx_fifo_wr_ptr = bus_space_read_4(t, h, GEM_RX_FIFO_WR_PTR);
1201 	rx_fifo_rd_ptr = bus_space_read_4(t, h, GEM_RX_FIFO_RD_PTR);
1202 	state = bus_space_read_4(t, h, GEM_MAC_MAC_STATE);
1203 	if ((state & GEM_MAC_STATE_OVERFLOW) == GEM_MAC_STATE_OVERFLOW &&
1204 	    ((rx_fifo_wr_ptr == rx_fifo_rd_ptr) ||
1205 	     ((sc->sc_rx_fifo_wr_ptr == rx_fifo_wr_ptr) &&
1206 	      (sc->sc_rx_fifo_rd_ptr == rx_fifo_rd_ptr)))) {
1207 		/*
1208 		 * The RX state machine is still in overflow state and
1209 		 * the RX FIFO write and read pointers seem to be
1210 		 * stuck.  Whack the chip over the head to get things
1211 		 * going again.
1212 		 */
1213 		gem_init(ifp);
1214 	}
1215 }
1216 
1217 void
1218 gem_watchdog(struct ifnet *ifp)
1219 {
1220 	struct gem_softc *sc = ifp->if_softc;
1221 
1222 	DPRINTF(sc, ("gem_watchdog: GEM_RX_CONFIG %x GEM_MAC_RX_STATUS %x "
1223 		"GEM_MAC_RX_CONFIG %x\n",
1224 		bus_space_read_4(sc->sc_bustag, sc->sc_h1, GEM_RX_CONFIG),
1225 		bus_space_read_4(sc->sc_bustag, sc->sc_h1, GEM_MAC_RX_STATUS),
1226 		bus_space_read_4(sc->sc_bustag, sc->sc_h1, GEM_MAC_RX_CONFIG)));
1227 
1228 	log(LOG_ERR, "%s: device timeout\n", sc->sc_dev.dv_xname);
1229 	++ifp->if_oerrors;
1230 
1231 	/* Try to get more packets going. */
1232 	gem_init(ifp);
1233 }
1234 
1235 /*
1236  * Initialize the MII Management Interface
1237  */
1238 void
1239 gem_mifinit(struct gem_softc *sc)
1240 {
1241 	bus_space_tag_t t = sc->sc_bustag;
1242 	bus_space_handle_t mif = sc->sc_h1;
1243 
1244 	/* Configure the MIF in frame mode */
1245 	sc->sc_mif_config = bus_space_read_4(t, mif, GEM_MIF_CONFIG);
1246 	sc->sc_mif_config &= ~GEM_MIF_CONFIG_BB_ENA;
1247 	bus_space_write_4(t, mif, GEM_MIF_CONFIG, sc->sc_mif_config);
1248 }
1249 
1250 /*
1251  * MII interface
1252  *
1253  * The GEM MII interface supports at least three different operating modes:
1254  *
1255  * Bitbang mode is implemented using data, clock and output enable registers.
1256  *
1257  * Frame mode is implemented by loading a complete frame into the frame
1258  * register and polling the valid bit for completion.
1259  *
1260  * Polling mode uses the frame register but completion is indicated by
1261  * an interrupt.
1262  *
1263  */
1264 int
1265 gem_mii_readreg(struct device *self, int phy, int reg)
1266 {
1267 	struct gem_softc *sc = (void *)self;
1268 	bus_space_tag_t t = sc->sc_bustag;
1269 	bus_space_handle_t mif = sc->sc_h1;
1270 	int n;
1271 	u_int32_t v;
1272 
1273 #ifdef GEM_DEBUG
1274 	if (sc->sc_debug)
1275 		printf("gem_mii_readreg: phy %d reg %d\n", phy, reg);
1276 #endif
1277 
1278 	/* Construct the frame command */
1279 	v = (reg << GEM_MIF_REG_SHIFT)	| (phy << GEM_MIF_PHY_SHIFT) |
1280 		GEM_MIF_FRAME_READ;
1281 
1282 	bus_space_write_4(t, mif, GEM_MIF_FRAME, v);
1283 	for (n = 0; n < 100; n++) {
1284 		DELAY(1);
1285 		v = bus_space_read_4(t, mif, GEM_MIF_FRAME);
1286 		if (v & GEM_MIF_FRAME_TA0)
1287 			return (v & GEM_MIF_FRAME_DATA);
1288 	}
1289 
1290 	printf("%s: mii_read timeout\n", sc->sc_dev.dv_xname);
1291 	return (0);
1292 }
1293 
1294 void
1295 gem_mii_writereg(struct device *self, int phy, int reg, int val)
1296 {
1297 	struct gem_softc *sc = (void *)self;
1298 	bus_space_tag_t t = sc->sc_bustag;
1299 	bus_space_handle_t mif = sc->sc_h1;
1300 	int n;
1301 	u_int32_t v;
1302 
1303 #ifdef GEM_DEBUG
1304 	if (sc->sc_debug)
1305 		printf("gem_mii_writereg: phy %d reg %d val %x\n",
1306 			phy, reg, val);
1307 #endif
1308 
1309 	/* Construct the frame command */
1310 	v = GEM_MIF_FRAME_WRITE			|
1311 	    (phy << GEM_MIF_PHY_SHIFT)		|
1312 	    (reg << GEM_MIF_REG_SHIFT)		|
1313 	    (val & GEM_MIF_FRAME_DATA);
1314 
1315 	bus_space_write_4(t, mif, GEM_MIF_FRAME, v);
1316 	for (n = 0; n < 100; n++) {
1317 		DELAY(1);
1318 		v = bus_space_read_4(t, mif, GEM_MIF_FRAME);
1319 		if (v & GEM_MIF_FRAME_TA0)
1320 			return;
1321 	}
1322 
1323 	printf("%s: mii_write timeout\n", sc->sc_dev.dv_xname);
1324 }
1325 
1326 void
1327 gem_mii_statchg(struct device *dev)
1328 {
1329 	struct gem_softc *sc = (void *)dev;
1330 #ifdef GEM_DEBUG
1331 	uint64_t instance = IFM_INST(sc->sc_mii.mii_media.ifm_cur->ifm_media);
1332 #endif
1333 	bus_space_tag_t t = sc->sc_bustag;
1334 	bus_space_handle_t mac = sc->sc_h1;
1335 	u_int32_t v;
1336 
1337 #ifdef GEM_DEBUG
1338 	if (sc->sc_debug)
1339 		printf("gem_mii_statchg: status change: phy = %lld\n", instance);
1340 #endif
1341 
1342 	/* Set tx full duplex options */
1343 	bus_space_write_4(t, mac, GEM_MAC_TX_CONFIG, 0);
1344 	delay(10000); /* reg must be cleared and delay before changing. */
1345 	v = GEM_MAC_TX_ENA_IPG0|GEM_MAC_TX_NGU|GEM_MAC_TX_NGU_LIMIT|
1346 		GEM_MAC_TX_ENABLE;
1347 	if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_FDX) != 0) {
1348 		v |= GEM_MAC_TX_IGN_CARRIER|GEM_MAC_TX_IGN_COLLIS;
1349 	}
1350 	bus_space_write_4(t, mac, GEM_MAC_TX_CONFIG, v);
1351 
1352 	/* XIF Configuration */
1353 	v = GEM_MAC_XIF_TX_MII_ENA;
1354 	v |= GEM_MAC_XIF_LINK_LED;
1355 
1356 	/* External MII needs echo disable if half duplex. */
1357 	if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_FDX) != 0)
1358 		/* turn on full duplex LED */
1359 		v |= GEM_MAC_XIF_FDPLX_LED;
1360 	else
1361 		/* half duplex -- disable echo */
1362 		v |= GEM_MAC_XIF_ECHO_DISABL;
1363 
1364 	switch (IFM_SUBTYPE(sc->sc_mii.mii_media_active)) {
1365 	case IFM_1000_T:  /* Gigabit using GMII interface */
1366 	case IFM_1000_SX:
1367 		v |= GEM_MAC_XIF_GMII_MODE;
1368 		break;
1369 	default:
1370 		v &= ~GEM_MAC_XIF_GMII_MODE;
1371 	}
1372 	bus_space_write_4(t, mac, GEM_MAC_XIF_CONFIG, v);
1373 
1374 	/*
1375 	 * 802.3x flow control
1376 	 */
1377 	v = bus_space_read_4(t, mac, GEM_MAC_CONTROL_CONFIG);
1378 	v &= ~(GEM_MAC_CC_RX_PAUSE | GEM_MAC_CC_TX_PAUSE);
1379 	if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_ETH_RXPAUSE) != 0)
1380 		v |= GEM_MAC_CC_RX_PAUSE;
1381 	if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_ETH_TXPAUSE) != 0)
1382 		v |= GEM_MAC_CC_TX_PAUSE;
1383 	bus_space_write_4(t, mac, GEM_MAC_CONTROL_CONFIG, v);
1384 }
1385 
1386 int
1387 gem_pcs_readreg(struct device *self, int phy, int reg)
1388 {
1389 	struct gem_softc *sc = (void *)self;
1390 	bus_space_tag_t t = sc->sc_bustag;
1391 	bus_space_handle_t pcs = sc->sc_h1;
1392 
1393 #ifdef GEM_DEBUG
1394 	if (sc->sc_debug)
1395 		printf("gem_pcs_readreg: phy %d reg %d\n", phy, reg);
1396 #endif
1397 
1398 	if (phy != GEM_PHYAD_EXTERNAL)
1399 		return (0);
1400 
1401 	switch (reg) {
1402 	case MII_BMCR:
1403 		reg = GEM_MII_CONTROL;
1404 		break;
1405 	case MII_BMSR:
1406 		reg = GEM_MII_STATUS;
1407 		break;
1408 	case MII_ANAR:
1409 		reg = GEM_MII_ANAR;
1410 		break;
1411 	case MII_ANLPAR:
1412 		reg = GEM_MII_ANLPAR;
1413 		break;
1414 	case MII_EXTSR:
1415 		return (EXTSR_1000XFDX|EXTSR_1000XHDX);
1416 	default:
1417 		return (0);
1418 	}
1419 
1420 	return bus_space_read_4(t, pcs, reg);
1421 }
1422 
1423 void
1424 gem_pcs_writereg(struct device *self, int phy, int reg, int val)
1425 {
1426 	struct gem_softc *sc = (void *)self;
1427 	bus_space_tag_t t = sc->sc_bustag;
1428 	bus_space_handle_t pcs = sc->sc_h1;
1429 	int reset = 0;
1430 
1431 #ifdef GEM_DEBUG
1432 	if (sc->sc_debug)
1433 		printf("gem_pcs_writereg: phy %d reg %d val %x\n",
1434 			phy, reg, val);
1435 #endif
1436 
1437 	if (phy != GEM_PHYAD_EXTERNAL)
1438 		return;
1439 
1440 	if (reg == MII_ANAR)
1441 		bus_space_write_4(t, pcs, GEM_MII_CONFIG, 0);
1442 
1443 	switch (reg) {
1444 	case MII_BMCR:
1445 		reset = (val & GEM_MII_CONTROL_RESET);
1446 		reg = GEM_MII_CONTROL;
1447 		break;
1448 	case MII_BMSR:
1449 		reg = GEM_MII_STATUS;
1450 		break;
1451 	case MII_ANAR:
1452 		reg = GEM_MII_ANAR;
1453 		break;
1454 	case MII_ANLPAR:
1455 		reg = GEM_MII_ANLPAR;
1456 		break;
1457 	default:
1458 		return;
1459 	}
1460 
1461 	bus_space_write_4(t, pcs, reg, val);
1462 
1463 	if (reset)
1464 		gem_bitwait(sc, pcs, GEM_MII_CONTROL, GEM_MII_CONTROL_RESET, 0);
1465 
1466 	if (reg == GEM_MII_ANAR || reset) {
1467 		bus_space_write_4(t, pcs, GEM_MII_SLINK_CONTROL,
1468 		    GEM_MII_SLINK_LOOPBACK|GEM_MII_SLINK_EN_SYNC_D);
1469 		bus_space_write_4(t, pcs, GEM_MII_CONFIG,
1470 		    GEM_MII_CONFIG_ENABLE);
1471 	}
1472 }
1473 
1474 int
1475 gem_mediachange(struct ifnet *ifp)
1476 {
1477 	struct gem_softc *sc = ifp->if_softc;
1478 	struct mii_data *mii = &sc->sc_mii;
1479 
1480 	if (mii->mii_instance) {
1481 		struct mii_softc *miisc;
1482 		LIST_FOREACH(miisc, &mii->mii_phys, mii_list)
1483 			mii_phy_reset(miisc);
1484 	}
1485 
1486 	return (mii_mediachg(&sc->sc_mii));
1487 }
1488 
1489 void
1490 gem_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
1491 {
1492 	struct gem_softc *sc = ifp->if_softc;
1493 
1494 	mii_pollstat(&sc->sc_mii);
1495 	ifmr->ifm_active = sc->sc_mii.mii_media_active;
1496 	ifmr->ifm_status = sc->sc_mii.mii_media_status;
1497 }
1498 
1499 /*
1500  * Process an ioctl request.
1501  */
1502 int
1503 gem_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1504 {
1505 	struct gem_softc *sc = ifp->if_softc;
1506 	struct ifreq *ifr = (struct ifreq *)data;
1507 	int s, error = 0;
1508 
1509 	s = splnet();
1510 
1511 	switch (cmd) {
1512 	case SIOCSIFADDR:
1513 		ifp->if_flags |= IFF_UP;
1514 		if ((ifp->if_flags & IFF_RUNNING) == 0)
1515 			gem_init(ifp);
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, prod;
1630 	int free = 0;
1631 
1632 	prod = status >> 19;
1633 	cons = sc->sc_tx_cons;
1634 	while (cons != prod) {
1635 		sd = &sc->sc_txd[cons];
1636 		if (sd->sd_mbuf != NULL) {
1637 			bus_dmamap_sync(sc->sc_dmatag, sd->sd_map, 0,
1638 			    sd->sd_map->dm_mapsize, BUS_DMASYNC_POSTWRITE);
1639 			bus_dmamap_unload(sc->sc_dmatag, sd->sd_map);
1640 			m_freem(sd->sd_mbuf);
1641 			sd->sd_mbuf = NULL;
1642 		}
1643 
1644 		free = 1;
1645 
1646 		cons++;
1647 		cons &= GEM_NTXDESC - 1;
1648 	}
1649 
1650 	if (free == 0)
1651 		return (0);
1652 
1653 	sc->sc_tx_cons = cons;
1654 
1655 	if (sc->sc_tx_prod == cons)
1656 		ifp->if_timer = 0;
1657 
1658 	if (ifq_is_oactive(&ifp->if_snd))
1659 		ifq_restart(&ifp->if_snd);
1660 
1661 	return (1);
1662 }
1663 
1664 int
1665 gem_load_mbuf(struct gem_softc *sc, struct gem_sxd *sd, struct mbuf *m)
1666 {
1667 	int error;
1668 
1669 	error = bus_dmamap_load_mbuf(sc->sc_dmatag, sd->sd_map, m,
1670 	    BUS_DMA_NOWAIT);
1671 	switch (error) {
1672 	case 0:
1673 		break;
1674 
1675 	case EFBIG: /* mbuf chain is too fragmented */
1676 		if (m_defrag(m, M_DONTWAIT) == 0 &&
1677 		    bus_dmamap_load_mbuf(sc->sc_dmatag, sd->sd_map, m,
1678 		    BUS_DMA_NOWAIT) == 0)
1679 		    	break;
1680 		/* FALLTHROUGH */
1681 	default:
1682 		return (1);
1683 	}
1684 
1685 	return (0);
1686 }
1687 
1688 void
1689 gem_start(struct ifqueue *ifq)
1690 {
1691 	struct ifnet *ifp = ifq->ifq_if;
1692 	struct gem_softc *sc = ifp->if_softc;
1693 	struct gem_sxd *sd;
1694 	struct mbuf *m;
1695 	uint64_t flags, nflags;
1696 	bus_dmamap_t map;
1697 	uint32_t prod;
1698 	uint32_t free, used = 0;
1699 	uint32_t first, last;
1700 	int i;
1701 
1702 	prod = sc->sc_tx_prod;
1703 
1704 	/* figure out space */
1705 	free = sc->sc_tx_cons;
1706 	if (free <= prod)
1707 		free += GEM_NTXDESC;
1708 	free -= prod;
1709 
1710 	bus_dmamap_sync(sc->sc_dmatag, sc->sc_cddmamap,
1711 	    0, sizeof(struct gem_desc) * GEM_NTXDESC,
1712 	    BUS_DMASYNC_PREWRITE);
1713 
1714 	for (;;) {
1715 		if (used + GEM_NTXSEGS + 1 > free) {
1716 			ifq_set_oactive(&ifp->if_snd);
1717 			break;
1718 		}
1719 
1720 		m = ifq_dequeue(ifq);
1721 		if (m == NULL)
1722 			break;
1723 
1724 		first = prod;
1725 		sd = &sc->sc_txd[first];
1726 		map = sd->sd_map;
1727 
1728 		if (gem_load_mbuf(sc, sd, m)) {
1729 			m_freem(m);
1730 			ifp->if_oerrors++;
1731 			continue;
1732 		}
1733 
1734 #if NBPFILTER > 0
1735 		if (ifp->if_bpf)
1736 			bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_OUT);
1737 #endif
1738 
1739 		bus_dmamap_sync(sc->sc_dmatag, map, 0, map->dm_mapsize,
1740 		    BUS_DMASYNC_PREWRITE);
1741 
1742 		nflags = GEM_TD_START_OF_PACKET;
1743 		for (i = 0; i < map->dm_nsegs; i++) {
1744 			flags = nflags |
1745 			    (map->dm_segs[i].ds_len & GEM_TD_BUFSIZE);
1746 
1747 			GEM_DMA_WRITE(sc, &sc->sc_txdescs[prod].gd_addr,
1748 			    map->dm_segs[i].ds_addr);
1749 			GEM_DMA_WRITE(sc, &sc->sc_txdescs[prod].gd_flags,
1750 			    flags);
1751 
1752 			last = prod;
1753 			prod++;
1754 			prod &= GEM_NTXDESC - 1;
1755 
1756 			nflags = 0;
1757 		}
1758 		GEM_DMA_WRITE(sc, &sc->sc_txdescs[last].gd_flags,
1759 		    GEM_TD_END_OF_PACKET | flags);
1760 
1761 		used += map->dm_nsegs;
1762 		sc->sc_txd[last].sd_mbuf = m;
1763 		sc->sc_txd[first].sd_map = sc->sc_txd[last].sd_map;
1764 		sc->sc_txd[last].sd_map = map;
1765 	}
1766 
1767 	bus_dmamap_sync(sc->sc_dmatag, sc->sc_cddmamap,
1768 	    0, sizeof(struct gem_desc) * GEM_NTXDESC,
1769 	    BUS_DMASYNC_POSTWRITE);
1770 
1771 	if (used == 0)
1772 		return;
1773 
1774 	/* Commit. */
1775 	sc->sc_tx_prod = prod;
1776 
1777 	/* Transmit. */
1778 	bus_space_write_4(sc->sc_bustag, sc->sc_h1, GEM_TX_KICK, prod);
1779 
1780 	/* Set timeout in case hardware has problems transmitting. */
1781 	ifp->if_timer = 5;
1782 }
1783