xref: /openbsd-src/sys/dev/ic/gem.c (revision a0747c9f67a4ae71ccb71e62a28d1ea19e06a63c)
1 /*	$OpenBSD: gem.c,v 1.126 2020/12/12 11:48:52 jan 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 	s = splnet();
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 	/*
453 	 * If buffer allocation fails, the receive ring may become
454 	 * empty. There is no receive interrupt to recover from that.
455 	 */
456 	if (if_rxr_inuse(&sc->sc_rx_ring) == 0) {
457 		gem_fill_rx_ring(sc);
458 		bus_space_write_4(t, mac, GEM_RX_KICK, sc->sc_rx_prod);
459 	}
460 
461 	mii_tick(&sc->sc_mii);
462 	splx(s);
463 
464 	timeout_add_sec(&sc->sc_tick_ch, 1);
465 }
466 
467 int
468 gem_bitwait(struct gem_softc *sc, bus_space_handle_t h, int r,
469    u_int32_t clr, u_int32_t set)
470 {
471 	int i;
472 	u_int32_t reg;
473 
474 	for (i = TRIES; i--; DELAY(100)) {
475 		reg = bus_space_read_4(sc->sc_bustag, h, r);
476 		if ((reg & clr) == 0 && (reg & set) == set)
477 			return (1);
478 	}
479 
480 	return (0);
481 }
482 
483 void
484 gem_reset(struct gem_softc *sc)
485 {
486 	bus_space_tag_t t = sc->sc_bustag;
487 	bus_space_handle_t h = sc->sc_h2;
488 	int s;
489 
490 	s = splnet();
491 	DPRINTF(sc, ("%s: gem_reset\n", sc->sc_dev.dv_xname));
492 	gem_reset_rx(sc);
493 	gem_reset_tx(sc);
494 
495 	/* Do a full reset */
496 	bus_space_write_4(t, h, GEM_RESET, GEM_RESET_RX|GEM_RESET_TX);
497 	if (!gem_bitwait(sc, h, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX, 0))
498 		printf("%s: cannot reset device\n", sc->sc_dev.dv_xname);
499 	splx(s);
500 }
501 
502 
503 /*
504  * Drain the receive queue.
505  */
506 void
507 gem_rxdrain(struct gem_softc *sc)
508 {
509 	struct gem_rxsoft *rxs;
510 	int i;
511 
512 	for (i = 0; i < GEM_NRXDESC; i++) {
513 		rxs = &sc->sc_rxsoft[i];
514 		if (rxs->rxs_mbuf != NULL) {
515 			bus_dmamap_sync(sc->sc_dmatag, rxs->rxs_dmamap, 0,
516 			    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);
517 			bus_dmamap_unload(sc->sc_dmatag, rxs->rxs_dmamap);
518 			m_freem(rxs->rxs_mbuf);
519 			rxs->rxs_mbuf = NULL;
520 		}
521 	}
522 	sc->sc_rx_prod = sc->sc_rx_cons = 0;
523 }
524 
525 /*
526  * Reset the whole thing.
527  */
528 void
529 gem_stop(struct ifnet *ifp, int softonly)
530 {
531 	struct gem_softc *sc = (struct gem_softc *)ifp->if_softc;
532 	struct gem_sxd *sd;
533 	u_int32_t i;
534 
535 	DPRINTF(sc, ("%s: gem_stop\n", sc->sc_dev.dv_xname));
536 
537 	timeout_del(&sc->sc_tick_ch);
538 
539 	/*
540 	 * Mark the interface down and cancel the watchdog timer.
541 	 */
542 	ifp->if_flags &= ~IFF_RUNNING;
543 	ifq_clr_oactive(&ifp->if_snd);
544 	ifp->if_timer = 0;
545 
546 	if (!softonly) {
547 		mii_down(&sc->sc_mii);
548 
549 		gem_reset_rx(sc);
550 		gem_reset_tx(sc);
551 	}
552 
553 	intr_barrier(sc->sc_ih);
554 	ifq_barrier(&ifp->if_snd);
555 
556 	KASSERT((ifp->if_flags & IFF_RUNNING) == 0);
557 
558 	/*
559 	 * Release any queued transmit buffers.
560 	 */
561 	for (i = 0; i < GEM_NTXDESC; i++) {
562 		sd = &sc->sc_txd[i];
563 		if (sd->sd_mbuf != NULL) {
564 			bus_dmamap_sync(sc->sc_dmatag, sd->sd_map, 0,
565 			    sd->sd_map->dm_mapsize, BUS_DMASYNC_POSTWRITE);
566 			bus_dmamap_unload(sc->sc_dmatag, sd->sd_map);
567 			m_freem(sd->sd_mbuf);
568 			sd->sd_mbuf = NULL;
569 		}
570 	}
571 	sc->sc_tx_cnt = sc->sc_tx_prod = sc->sc_tx_cons = 0;
572 
573 	gem_rxdrain(sc);
574 }
575 
576 
577 /*
578  * Reset the receiver
579  */
580 int
581 gem_reset_rx(struct gem_softc *sc)
582 {
583 	bus_space_tag_t t = sc->sc_bustag;
584 	bus_space_handle_t h = sc->sc_h1, h2 = sc->sc_h2;
585 
586 	/*
587 	 * Resetting while DMA is in progress can cause a bus hang, so we
588 	 * disable DMA first.
589 	 */
590 	gem_disable_rx(sc);
591 	bus_space_write_4(t, h, GEM_RX_CONFIG, 0);
592 	/* Wait till it finishes */
593 	if (!gem_bitwait(sc, h, GEM_RX_CONFIG, 1, 0))
594 		printf("%s: cannot disable rx dma\n", sc->sc_dev.dv_xname);
595 	/* Wait 5ms extra. */
596 	delay(5000);
597 
598 	/* Finally, reset the ERX */
599 	bus_space_write_4(t, h2, GEM_RESET, GEM_RESET_RX);
600 	/* Wait till it finishes */
601 	if (!gem_bitwait(sc, h2, GEM_RESET, GEM_RESET_RX, 0)) {
602 		printf("%s: cannot reset receiver\n", sc->sc_dev.dv_xname);
603 		return (1);
604 	}
605 	return (0);
606 }
607 
608 
609 /*
610  * Reset the transmitter
611  */
612 int
613 gem_reset_tx(struct gem_softc *sc)
614 {
615 	bus_space_tag_t t = sc->sc_bustag;
616 	bus_space_handle_t h = sc->sc_h1, h2 = sc->sc_h2;
617 
618 	/*
619 	 * Resetting while DMA is in progress can cause a bus hang, so we
620 	 * disable DMA first.
621 	 */
622 	gem_disable_tx(sc);
623 	bus_space_write_4(t, h, GEM_TX_CONFIG, 0);
624 	/* Wait till it finishes */
625 	if (!gem_bitwait(sc, h, GEM_TX_CONFIG, 1, 0))
626 		printf("%s: cannot disable tx dma\n", sc->sc_dev.dv_xname);
627 	/* Wait 5ms extra. */
628 	delay(5000);
629 
630 	/* Finally, reset the ETX */
631 	bus_space_write_4(t, h2, GEM_RESET, GEM_RESET_TX);
632 	/* Wait till it finishes */
633 	if (!gem_bitwait(sc, h2, GEM_RESET, GEM_RESET_TX, 0)) {
634 		printf("%s: cannot reset transmitter\n",
635 			sc->sc_dev.dv_xname);
636 		return (1);
637 	}
638 	return (0);
639 }
640 
641 /*
642  * Disable receiver.
643  */
644 int
645 gem_disable_rx(struct gem_softc *sc)
646 {
647 	bus_space_tag_t t = sc->sc_bustag;
648 	bus_space_handle_t h = sc->sc_h1;
649 	u_int32_t cfg;
650 
651 	/* Flip the enable bit */
652 	cfg = bus_space_read_4(t, h, GEM_MAC_RX_CONFIG);
653 	cfg &= ~GEM_MAC_RX_ENABLE;
654 	bus_space_write_4(t, h, GEM_MAC_RX_CONFIG, cfg);
655 
656 	/* Wait for it to finish */
657 	return (gem_bitwait(sc, h, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0));
658 }
659 
660 /*
661  * Disable transmitter.
662  */
663 int
664 gem_disable_tx(struct gem_softc *sc)
665 {
666 	bus_space_tag_t t = sc->sc_bustag;
667 	bus_space_handle_t h = sc->sc_h1;
668 	u_int32_t cfg;
669 
670 	/* Flip the enable bit */
671 	cfg = bus_space_read_4(t, h, GEM_MAC_TX_CONFIG);
672 	cfg &= ~GEM_MAC_TX_ENABLE;
673 	bus_space_write_4(t, h, GEM_MAC_TX_CONFIG, cfg);
674 
675 	/* Wait for it to finish */
676 	return (gem_bitwait(sc, h, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0));
677 }
678 
679 /*
680  * Initialize interface.
681  */
682 int
683 gem_meminit(struct gem_softc *sc)
684 {
685 	int i;
686 
687 	/*
688 	 * Initialize the transmit descriptor ring.
689 	 */
690 	for (i = 0; i < GEM_NTXDESC; i++) {
691 		sc->sc_txdescs[i].gd_flags = 0;
692 		sc->sc_txdescs[i].gd_addr = 0;
693 	}
694 	GEM_CDTXSYNC(sc, 0, GEM_NTXDESC,
695 	    BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
696 
697 	/*
698 	 * Initialize the receive descriptor and receive job
699 	 * descriptor rings.
700 	 */
701 	for (i = 0; i < GEM_NRXDESC; i++) {
702 		sc->sc_rxdescs[i].gd_flags = 0;
703 		sc->sc_rxdescs[i].gd_addr = 0;
704 	}
705 	/* Hardware reads RX descriptors in multiples of four. */
706 	if_rxr_init(&sc->sc_rx_ring, 4, GEM_NRXDESC - 4);
707 	gem_fill_rx_ring(sc);
708 
709 	return (0);
710 }
711 
712 int
713 gem_ringsize(int sz)
714 {
715 	switch (sz) {
716 	case 32:
717 		return GEM_RING_SZ_32;
718 	case 64:
719 		return GEM_RING_SZ_64;
720 	case 128:
721 		return GEM_RING_SZ_128;
722 	case 256:
723 		return GEM_RING_SZ_256;
724 	case 512:
725 		return GEM_RING_SZ_512;
726 	case 1024:
727 		return GEM_RING_SZ_1024;
728 	case 2048:
729 		return GEM_RING_SZ_2048;
730 	case 4096:
731 		return GEM_RING_SZ_4096;
732 	case 8192:
733 		return GEM_RING_SZ_8192;
734 	default:
735 		printf("gem: invalid Receive Descriptor ring size %d\n", sz);
736 		return GEM_RING_SZ_32;
737 	}
738 }
739 
740 /*
741  * Initialization of interface; set up initialization block
742  * and transmit/receive descriptor rings.
743  */
744 int
745 gem_init(struct ifnet *ifp)
746 {
747 
748 	struct gem_softc *sc = (struct gem_softc *)ifp->if_softc;
749 	bus_space_tag_t t = sc->sc_bustag;
750 	bus_space_handle_t h = sc->sc_h1;
751 	int s;
752 	u_int32_t v;
753 
754 	s = splnet();
755 
756 	DPRINTF(sc, ("%s: gem_init: calling stop\n", sc->sc_dev.dv_xname));
757 	/*
758 	 * Initialization sequence. The numbered steps below correspond
759 	 * to the sequence outlined in section 6.3.5.1 in the Ethernet
760 	 * Channel Engine manual (part of the PCIO manual).
761 	 * See also the STP2002-STQ document from Sun Microsystems.
762 	 */
763 
764 	/* step 1 & 2. Reset the Ethernet Channel */
765 	gem_stop(ifp, 0);
766 	gem_reset(sc);
767 	DPRINTF(sc, ("%s: gem_init: restarting\n", sc->sc_dev.dv_xname));
768 
769 	/* Re-initialize the MIF */
770 	gem_mifinit(sc);
771 
772 	/* Call MI reset function if any */
773 	if (sc->sc_hwreset)
774 		(*sc->sc_hwreset)(sc);
775 
776 	/* step 3. Setup data structures in host memory */
777 	gem_meminit(sc);
778 
779 	/* step 4. TX MAC registers & counters */
780 	gem_init_regs(sc);
781 
782 	/* step 5. RX MAC registers & counters */
783 	gem_iff(sc);
784 
785 	/* step 6 & 7. Program Descriptor Ring Base Addresses */
786 	bus_space_write_4(t, h, GEM_TX_RING_PTR_HI,
787 	    (((uint64_t)GEM_CDTXADDR(sc,0)) >> 32));
788 	bus_space_write_4(t, h, GEM_TX_RING_PTR_LO, GEM_CDTXADDR(sc, 0));
789 
790 	bus_space_write_4(t, h, GEM_RX_RING_PTR_HI,
791 	    (((uint64_t)GEM_CDRXADDR(sc,0)) >> 32));
792 	bus_space_write_4(t, h, GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
793 
794 	/* step 8. Global Configuration & Interrupt Mask */
795 	bus_space_write_4(t, h, GEM_INTMASK,
796 		      ~(GEM_INTR_TX_INTME|
797 			GEM_INTR_TX_EMPTY|
798 			GEM_INTR_RX_DONE|GEM_INTR_RX_NOBUF|
799 			GEM_INTR_RX_TAG_ERR|GEM_INTR_PCS|
800 			GEM_INTR_MAC_CONTROL|GEM_INTR_MIF|
801 			GEM_INTR_BERR));
802 	bus_space_write_4(t, h, GEM_MAC_RX_MASK,
803 	    GEM_MAC_RX_DONE|GEM_MAC_RX_FRAME_CNT);
804 	bus_space_write_4(t, h, GEM_MAC_TX_MASK, 0xffff); /* XXXX */
805 	bus_space_write_4(t, h, GEM_MAC_CONTROL_MASK, 0); /* XXXX */
806 
807 	/* step 9. ETX Configuration: use mostly default values */
808 
809 	/* Enable DMA */
810 	v = gem_ringsize(GEM_NTXDESC /*XXX*/);
811 	v |= ((sc->sc_variant == GEM_SUN_ERI ? 0x100 : 0x04ff) << 10) &
812 	    GEM_TX_CONFIG_TXFIFO_TH;
813 	bus_space_write_4(t, h, GEM_TX_CONFIG, v | GEM_TX_CONFIG_TXDMA_EN);
814 	bus_space_write_4(t, h, GEM_TX_KICK, 0);
815 
816 	/* step 10. ERX Configuration */
817 
818 	/* Encode Receive Descriptor ring size: four possible values */
819 	v = gem_ringsize(GEM_NRXDESC /*XXX*/);
820 	/* Enable DMA */
821 	bus_space_write_4(t, h, GEM_RX_CONFIG,
822 		v|(GEM_THRSH_1024<<GEM_RX_CONFIG_FIFO_THRS_SHIFT)|
823 		(2<<GEM_RX_CONFIG_FBOFF_SHFT)|GEM_RX_CONFIG_RXDMA_EN|
824 		(0<<GEM_RX_CONFIG_CXM_START_SHFT));
825 	/*
826 	 * The following value is for an OFF Threshold of about 3/4 full
827 	 * and an ON Threshold of 1/4 full.
828 	 */
829 	bus_space_write_4(t, h, GEM_RX_PAUSE_THRESH,
830 	    (3 * sc->sc_rxfifosize / 256) |
831 	    ((sc->sc_rxfifosize / 256) << 12));
832 	bus_space_write_4(t, h, GEM_RX_BLANKING, (6 << 12) | 6);
833 
834 	/* step 11. Configure Media */
835 	mii_mediachg(&sc->sc_mii);
836 
837 	/* step 12. RX_MAC Configuration Register */
838 	v = bus_space_read_4(t, h, GEM_MAC_RX_CONFIG);
839 	v |= GEM_MAC_RX_ENABLE | GEM_MAC_RX_STRIP_CRC;
840 	bus_space_write_4(t, h, GEM_MAC_RX_CONFIG, v);
841 
842 	/* step 14. Issue Transmit Pending command */
843 
844 	/* Call MI initialization function if any */
845 	if (sc->sc_hwinit)
846 		(*sc->sc_hwinit)(sc);
847 
848 	/* step 15.  Give the receiver a swift kick */
849 	bus_space_write_4(t, h, GEM_RX_KICK, sc->sc_rx_prod);
850 
851 	/* Start the one second timer. */
852 	timeout_add_sec(&sc->sc_tick_ch, 1);
853 
854 	ifp->if_flags |= IFF_RUNNING;
855 	ifq_clr_oactive(&ifp->if_snd);
856 
857 	splx(s);
858 
859 	return (0);
860 }
861 
862 void
863 gem_init_regs(struct gem_softc *sc)
864 {
865 	bus_space_tag_t t = sc->sc_bustag;
866 	bus_space_handle_t h = sc->sc_h1;
867 	u_int32_t v;
868 
869 	/* These regs are not cleared on reset */
870 	sc->sc_inited = 0;
871 	if (!sc->sc_inited) {
872 		/* Load recommended values */
873 		bus_space_write_4(t, h, GEM_MAC_IPG0, 0x00);
874 		bus_space_write_4(t, h, GEM_MAC_IPG1, 0x08);
875 		bus_space_write_4(t, h, GEM_MAC_IPG2, 0x04);
876 
877 		bus_space_write_4(t, h, GEM_MAC_MAC_MIN_FRAME, ETHER_MIN_LEN);
878 		/* Max frame and max burst size */
879 		bus_space_write_4(t, h, GEM_MAC_MAC_MAX_FRAME,
880 		    (ETHER_MAX_LEN + ETHER_VLAN_ENCAP_LEN) | (0x2000 << 16));
881 
882 		bus_space_write_4(t, h, GEM_MAC_PREAMBLE_LEN, 0x07);
883 		bus_space_write_4(t, h, GEM_MAC_JAM_SIZE, 0x04);
884 		bus_space_write_4(t, h, GEM_MAC_ATTEMPT_LIMIT, 0x10);
885 		bus_space_write_4(t, h, GEM_MAC_CONTROL_TYPE, 0x8088);
886 		bus_space_write_4(t, h, GEM_MAC_RANDOM_SEED,
887 		    ((sc->sc_arpcom.ac_enaddr[5]<<8)|sc->sc_arpcom.ac_enaddr[4])&0x3ff);
888 
889 		/* Secondary MAC addr set to 0:0:0:0:0:0 */
890 		bus_space_write_4(t, h, GEM_MAC_ADDR3, 0);
891 		bus_space_write_4(t, h, GEM_MAC_ADDR4, 0);
892 		bus_space_write_4(t, h, GEM_MAC_ADDR5, 0);
893 
894 		/* MAC control addr set to 0:1:c2:0:1:80 */
895 		bus_space_write_4(t, h, GEM_MAC_ADDR6, 0x0001);
896 		bus_space_write_4(t, h, GEM_MAC_ADDR7, 0xc200);
897 		bus_space_write_4(t, h, GEM_MAC_ADDR8, 0x0180);
898 
899 		/* MAC filter addr set to 0:0:0:0:0:0 */
900 		bus_space_write_4(t, h, GEM_MAC_ADDR_FILTER0, 0);
901 		bus_space_write_4(t, h, GEM_MAC_ADDR_FILTER1, 0);
902 		bus_space_write_4(t, h, GEM_MAC_ADDR_FILTER2, 0);
903 
904 		bus_space_write_4(t, h, GEM_MAC_ADR_FLT_MASK1_2, 0);
905 		bus_space_write_4(t, h, GEM_MAC_ADR_FLT_MASK0, 0);
906 
907 		sc->sc_inited = 1;
908 	}
909 
910 	/* Counters need to be zeroed */
911 	bus_space_write_4(t, h, GEM_MAC_NORM_COLL_CNT, 0);
912 	bus_space_write_4(t, h, GEM_MAC_FIRST_COLL_CNT, 0);
913 	bus_space_write_4(t, h, GEM_MAC_EXCESS_COLL_CNT, 0);
914 	bus_space_write_4(t, h, GEM_MAC_LATE_COLL_CNT, 0);
915 	bus_space_write_4(t, h, GEM_MAC_DEFER_TMR_CNT, 0);
916 	bus_space_write_4(t, h, GEM_MAC_PEAK_ATTEMPTS, 0);
917 	bus_space_write_4(t, h, GEM_MAC_RX_FRAME_COUNT, 0);
918 	bus_space_write_4(t, h, GEM_MAC_RX_LEN_ERR_CNT, 0);
919 	bus_space_write_4(t, h, GEM_MAC_RX_ALIGN_ERR, 0);
920 	bus_space_write_4(t, h, GEM_MAC_RX_CRC_ERR_CNT, 0);
921 	bus_space_write_4(t, h, GEM_MAC_RX_CODE_VIOL, 0);
922 
923 	/* Set XOFF PAUSE time */
924 	bus_space_write_4(t, h, GEM_MAC_SEND_PAUSE_CMD, 0x1bf0);
925 
926 	/*
927 	 * Set the internal arbitration to "infinite" bursts of the
928 	 * maximum length of 31 * 64 bytes so DMA transfers aren't
929 	 * split up in cache line size chunks. This greatly improves
930 	 * especially RX performance.
931 	 * Enable silicon bug workarounds for the Apple variants.
932 	 */
933 	v = GEM_CONFIG_TXDMA_LIMIT | GEM_CONFIG_RXDMA_LIMIT;
934 	if (sc->sc_pci)
935 		v |= GEM_CONFIG_BURST_INF;
936 	else
937 		v |= GEM_CONFIG_BURST_64;
938 	if (sc->sc_variant != GEM_SUN_GEM && sc->sc_variant != GEM_SUN_ERI)
939 		v |= GEM_CONFIG_RONPAULBIT | GEM_CONFIG_BUG2FIX;
940 	bus_space_write_4(t, h, GEM_CONFIG, v);
941 
942 	/*
943 	 * Set the station address.
944 	 */
945 	bus_space_write_4(t, h, GEM_MAC_ADDR0,
946 		(sc->sc_arpcom.ac_enaddr[4]<<8) | sc->sc_arpcom.ac_enaddr[5]);
947 	bus_space_write_4(t, h, GEM_MAC_ADDR1,
948 		(sc->sc_arpcom.ac_enaddr[2]<<8) | sc->sc_arpcom.ac_enaddr[3]);
949 	bus_space_write_4(t, h, GEM_MAC_ADDR2,
950 		(sc->sc_arpcom.ac_enaddr[0]<<8) | sc->sc_arpcom.ac_enaddr[1]);
951 }
952 
953 /*
954  * Receive interrupt.
955  */
956 int
957 gem_rint(struct gem_softc *sc)
958 {
959 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
960 	bus_space_tag_t t = sc->sc_bustag;
961 	bus_space_handle_t h = sc->sc_h1;
962 	struct gem_rxsoft *rxs;
963 	struct mbuf_list ml = MBUF_LIST_INITIALIZER();
964 	struct mbuf *m;
965 	u_int64_t rxstat;
966 	int i, len;
967 
968 	if (if_rxr_inuse(&sc->sc_rx_ring) == 0)
969 		return (0);
970 
971 	for (i = sc->sc_rx_cons; if_rxr_inuse(&sc->sc_rx_ring) > 0;
972 	    i = GEM_NEXTRX(i)) {
973 		rxs = &sc->sc_rxsoft[i];
974 
975 		GEM_CDRXSYNC(sc, i,
976 		    BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
977 
978 		rxstat = GEM_DMA_READ(sc, &sc->sc_rxdescs[i].gd_flags);
979 
980 		if (rxstat & GEM_RD_OWN) {
981 			/* We have processed all of the receive buffers. */
982 			break;
983 		}
984 
985 		bus_dmamap_sync(sc->sc_dmatag, rxs->rxs_dmamap, 0,
986 		    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);
987 		bus_dmamap_unload(sc->sc_dmatag, rxs->rxs_dmamap);
988 
989 		m = rxs->rxs_mbuf;
990 		rxs->rxs_mbuf = NULL;
991 
992 		if_rxr_put(&sc->sc_rx_ring, 1);
993 
994 		if (rxstat & GEM_RD_BAD_CRC) {
995 			ifp->if_ierrors++;
996 #ifdef GEM_DEBUG
997 			printf("%s: receive error: CRC error\n",
998 				sc->sc_dev.dv_xname);
999 #endif
1000 			m_freem(m);
1001 			continue;
1002 		}
1003 
1004 #ifdef GEM_DEBUG
1005 		if (ifp->if_flags & IFF_DEBUG) {
1006 			printf("    rxsoft %p descriptor %d: ", rxs, i);
1007 			printf("gd_flags: 0x%016llx\t", (long long)
1008 				GEM_DMA_READ(sc, &sc->sc_rxdescs[i].gd_flags));
1009 			printf("gd_addr: 0x%016llx\n", (long long)
1010 				GEM_DMA_READ(sc, &sc->sc_rxdescs[i].gd_addr));
1011 		}
1012 #endif
1013 
1014 		/* No errors; receive the packet. */
1015 		len = GEM_RD_BUFLEN(rxstat);
1016 
1017 		m->m_data += 2; /* We're already off by two */
1018 		m->m_pkthdr.len = m->m_len = len;
1019 
1020 		ml_enqueue(&ml, m);
1021 	}
1022 
1023 	if (ifiq_input(&ifp->if_rcv, &ml))
1024 		if_rxr_livelocked(&sc->sc_rx_ring);
1025 
1026 	/* Update the receive pointer. */
1027 	sc->sc_rx_cons = i;
1028 	gem_fill_rx_ring(sc);
1029 	bus_space_write_4(t, h, GEM_RX_KICK, sc->sc_rx_prod);
1030 
1031 	DPRINTF(sc, ("gem_rint: done sc->sc_rx_cons %d, complete %d\n",
1032 		sc->sc_rx_cons, bus_space_read_4(t, h, GEM_RX_COMPLETION)));
1033 
1034 	return (1);
1035 }
1036 
1037 void
1038 gem_fill_rx_ring(struct gem_softc *sc)
1039 {
1040 	u_int slots;
1041 
1042 	for (slots = if_rxr_get(&sc->sc_rx_ring, GEM_NRXDESC - 4);
1043 	    slots > 0; slots--) {
1044 		if (gem_add_rxbuf(sc, sc->sc_rx_prod))
1045 			break;
1046 	}
1047 	if_rxr_put(&sc->sc_rx_ring, slots);
1048 }
1049 
1050 /*
1051  * Add a receive buffer to the indicated descriptor.
1052  */
1053 int
1054 gem_add_rxbuf(struct gem_softc *sc, int idx)
1055 {
1056 	struct gem_rxsoft *rxs = &sc->sc_rxsoft[idx];
1057 	struct mbuf *m;
1058 	int error;
1059 
1060 	m = MCLGETL(NULL, M_DONTWAIT, MCLBYTES);
1061 	if (!m)
1062 		return (ENOBUFS);
1063 	m->m_len = m->m_pkthdr.len = MCLBYTES;
1064 
1065 #ifdef GEM_DEBUG
1066 /* bzero the packet to check dma */
1067 	memset(m->m_ext.ext_buf, 0, m->m_ext.ext_size);
1068 #endif
1069 
1070 	rxs->rxs_mbuf = m;
1071 
1072 	error = bus_dmamap_load_mbuf(sc->sc_dmatag, rxs->rxs_dmamap, m,
1073 	    BUS_DMA_READ|BUS_DMA_NOWAIT);
1074 	if (error) {
1075 		printf("%s: can't load rx DMA map %d, error = %d\n",
1076 		    sc->sc_dev.dv_xname, idx, error);
1077 		panic("gem_add_rxbuf");	/* XXX */
1078 	}
1079 
1080 	bus_dmamap_sync(sc->sc_dmatag, rxs->rxs_dmamap, 0,
1081 	    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_PREREAD);
1082 
1083 	GEM_INIT_RXDESC(sc, idx);
1084 
1085 	sc->sc_rx_prod = GEM_NEXTRX(sc->sc_rx_prod);
1086 
1087 	return (0);
1088 }
1089 
1090 int
1091 gem_eint(struct gem_softc *sc, u_int status)
1092 {
1093 	if ((status & GEM_INTR_MIF) != 0) {
1094 #ifdef GEM_DEBUG
1095 		printf("%s: link status changed\n", sc->sc_dev.dv_xname);
1096 #endif
1097 		return (1);
1098 	}
1099 
1100 	printf("%s: status=%b\n", sc->sc_dev.dv_xname, status, GEM_INTR_BITS);
1101 	return (1);
1102 }
1103 
1104 int
1105 gem_pint(struct gem_softc *sc)
1106 {
1107 	bus_space_tag_t t = sc->sc_bustag;
1108 	bus_space_handle_t seb = sc->sc_h1;
1109 	u_int32_t status;
1110 
1111 	status = bus_space_read_4(t, seb, GEM_MII_INTERRUP_STATUS);
1112 	status |= bus_space_read_4(t, seb, GEM_MII_INTERRUP_STATUS);
1113 #ifdef GEM_DEBUG
1114 	if (status)
1115 		printf("%s: link status changed\n", sc->sc_dev.dv_xname);
1116 #endif
1117 	return (1);
1118 }
1119 
1120 int
1121 gem_intr(void *v)
1122 {
1123 	struct gem_softc *sc = (struct gem_softc *)v;
1124 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
1125 	bus_space_tag_t t = sc->sc_bustag;
1126 	bus_space_handle_t seb = sc->sc_h1;
1127 	u_int32_t status;
1128 	int r = 0;
1129 
1130 	status = bus_space_read_4(t, seb, GEM_STATUS);
1131 	DPRINTF(sc, ("%s: gem_intr: cplt %xstatus %b\n",
1132 		sc->sc_dev.dv_xname, (status>>19), status, GEM_INTR_BITS));
1133 
1134 	if (status == 0xffffffff)
1135 		return (0);
1136 
1137 	if ((status & GEM_INTR_PCS) != 0)
1138 		r |= gem_pint(sc);
1139 
1140 	if ((status & (GEM_INTR_RX_TAG_ERR | GEM_INTR_BERR)) != 0)
1141 		r |= gem_eint(sc, status);
1142 
1143 	if ((status & (GEM_INTR_TX_EMPTY | GEM_INTR_TX_INTME)) != 0)
1144 		r |= gem_tint(sc, status);
1145 
1146 	if ((status & (GEM_INTR_RX_DONE | GEM_INTR_RX_NOBUF)) != 0)
1147 		r |= gem_rint(sc);
1148 
1149 	/* We should eventually do more than just print out error stats. */
1150 	if (status & GEM_INTR_TX_MAC) {
1151 		int txstat = bus_space_read_4(t, seb, GEM_MAC_TX_STATUS);
1152 #ifdef GEM_DEBUG
1153 		if (txstat & ~GEM_MAC_TX_XMIT_DONE)
1154 			printf("%s: MAC tx fault, status %x\n",
1155 			    sc->sc_dev.dv_xname, txstat);
1156 #endif
1157 		if (txstat & (GEM_MAC_TX_UNDERRUN | GEM_MAC_TX_PKT_TOO_LONG)) {
1158 			KERNEL_LOCK();
1159 			gem_init(ifp);
1160 			KERNEL_UNLOCK();
1161 		}
1162 	}
1163 	if (status & GEM_INTR_RX_MAC) {
1164 		int rxstat = bus_space_read_4(t, seb, GEM_MAC_RX_STATUS);
1165 #ifdef GEM_DEBUG
1166  		if (rxstat & ~GEM_MAC_RX_DONE)
1167  			printf("%s: MAC rx fault, status %x\n",
1168  			    sc->sc_dev.dv_xname, rxstat);
1169 #endif
1170 		if (rxstat & GEM_MAC_RX_OVERFLOW) {
1171 			ifp->if_ierrors++;
1172 
1173 			/*
1174 			 * Apparently a silicon bug causes ERI to hang
1175 			 * from time to time.  So if we detect an RX
1176 			 * FIFO overflow, we fire off a timer, and
1177 			 * check whether we're still making progress
1178 			 * by looking at the RX FIFO write and read
1179 			 * pointers.
1180 			 */
1181 			sc->sc_rx_fifo_wr_ptr =
1182 				bus_space_read_4(t, seb, GEM_RX_FIFO_WR_PTR);
1183 			sc->sc_rx_fifo_rd_ptr =
1184 				bus_space_read_4(t, seb, GEM_RX_FIFO_RD_PTR);
1185 			timeout_add_msec(&sc->sc_rx_watchdog, 400);
1186 		}
1187 #ifdef GEM_DEBUG
1188 		else if (rxstat & ~(GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT))
1189 			printf("%s: MAC rx fault, status %x\n",
1190 			    sc->sc_dev.dv_xname, rxstat);
1191 #endif
1192 	}
1193 	return (r);
1194 }
1195 
1196 void
1197 gem_rx_watchdog(void *arg)
1198 {
1199 	struct gem_softc *sc = arg;
1200 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
1201 	bus_space_tag_t t = sc->sc_bustag;
1202 	bus_space_handle_t h = sc->sc_h1;
1203 	u_int32_t rx_fifo_wr_ptr;
1204 	u_int32_t rx_fifo_rd_ptr;
1205 	u_int32_t state;
1206 
1207 	if ((ifp->if_flags & IFF_RUNNING) == 0)
1208 		return;
1209 
1210 	rx_fifo_wr_ptr = bus_space_read_4(t, h, GEM_RX_FIFO_WR_PTR);
1211 	rx_fifo_rd_ptr = bus_space_read_4(t, h, GEM_RX_FIFO_RD_PTR);
1212 	state = bus_space_read_4(t, h, GEM_MAC_MAC_STATE);
1213 	if ((state & GEM_MAC_STATE_OVERFLOW) == GEM_MAC_STATE_OVERFLOW) {
1214 		if ((rx_fifo_wr_ptr == rx_fifo_rd_ptr) ||
1215 		     ((sc->sc_rx_fifo_wr_ptr == rx_fifo_wr_ptr) &&
1216 		      (sc->sc_rx_fifo_rd_ptr == rx_fifo_rd_ptr))) {
1217 			/*
1218 			 * The RX state machine is still in overflow state and
1219 			 * the RX FIFO write and read pointers seem to be
1220 			 * stuck.  Whack the chip over the head to get things
1221 			 * going again.
1222 			 */
1223 			gem_init(ifp);
1224 		} else {
1225 			/*
1226 			 * We made some progress, but is not certain that the
1227 			 * overflow condition has been resolved.  Check again.
1228 			 */
1229 			sc->sc_rx_fifo_wr_ptr = rx_fifo_wr_ptr;
1230 			sc->sc_rx_fifo_rd_ptr = rx_fifo_rd_ptr;
1231 			timeout_add_msec(&sc->sc_rx_watchdog, 400);
1232 		}
1233 	}
1234 }
1235 
1236 void
1237 gem_watchdog(struct ifnet *ifp)
1238 {
1239 	struct gem_softc *sc = ifp->if_softc;
1240 
1241 	DPRINTF(sc, ("gem_watchdog: GEM_RX_CONFIG %x GEM_MAC_RX_STATUS %x "
1242 		"GEM_MAC_RX_CONFIG %x\n",
1243 		bus_space_read_4(sc->sc_bustag, sc->sc_h1, GEM_RX_CONFIG),
1244 		bus_space_read_4(sc->sc_bustag, sc->sc_h1, GEM_MAC_RX_STATUS),
1245 		bus_space_read_4(sc->sc_bustag, sc->sc_h1, GEM_MAC_RX_CONFIG)));
1246 
1247 	log(LOG_ERR, "%s: device timeout\n", sc->sc_dev.dv_xname);
1248 	++ifp->if_oerrors;
1249 
1250 	/* Try to get more packets going. */
1251 	gem_init(ifp);
1252 }
1253 
1254 /*
1255  * Initialize the MII Management Interface
1256  */
1257 void
1258 gem_mifinit(struct gem_softc *sc)
1259 {
1260 	bus_space_tag_t t = sc->sc_bustag;
1261 	bus_space_handle_t mif = sc->sc_h1;
1262 
1263 	/* Configure the MIF in frame mode */
1264 	sc->sc_mif_config = bus_space_read_4(t, mif, GEM_MIF_CONFIG);
1265 	sc->sc_mif_config &= ~GEM_MIF_CONFIG_BB_ENA;
1266 	bus_space_write_4(t, mif, GEM_MIF_CONFIG, sc->sc_mif_config);
1267 }
1268 
1269 /*
1270  * MII interface
1271  *
1272  * The GEM MII interface supports at least three different operating modes:
1273  *
1274  * Bitbang mode is implemented using data, clock and output enable registers.
1275  *
1276  * Frame mode is implemented by loading a complete frame into the frame
1277  * register and polling the valid bit for completion.
1278  *
1279  * Polling mode uses the frame register but completion is indicated by
1280  * an interrupt.
1281  *
1282  */
1283 int
1284 gem_mii_readreg(struct device *self, int phy, int reg)
1285 {
1286 	struct gem_softc *sc = (void *)self;
1287 	bus_space_tag_t t = sc->sc_bustag;
1288 	bus_space_handle_t mif = sc->sc_h1;
1289 	int n;
1290 	u_int32_t v;
1291 
1292 #ifdef GEM_DEBUG
1293 	if (sc->sc_debug)
1294 		printf("gem_mii_readreg: phy %d reg %d\n", phy, reg);
1295 #endif
1296 
1297 	/* Construct the frame command */
1298 	v = (reg << GEM_MIF_REG_SHIFT)	| (phy << GEM_MIF_PHY_SHIFT) |
1299 		GEM_MIF_FRAME_READ;
1300 
1301 	bus_space_write_4(t, mif, GEM_MIF_FRAME, v);
1302 	for (n = 0; n < 100; n++) {
1303 		DELAY(1);
1304 		v = bus_space_read_4(t, mif, GEM_MIF_FRAME);
1305 		if (v & GEM_MIF_FRAME_TA0)
1306 			return (v & GEM_MIF_FRAME_DATA);
1307 	}
1308 
1309 	printf("%s: mii_read timeout\n", sc->sc_dev.dv_xname);
1310 	return (0);
1311 }
1312 
1313 void
1314 gem_mii_writereg(struct device *self, int phy, int reg, int val)
1315 {
1316 	struct gem_softc *sc = (void *)self;
1317 	bus_space_tag_t t = sc->sc_bustag;
1318 	bus_space_handle_t mif = sc->sc_h1;
1319 	int n;
1320 	u_int32_t v;
1321 
1322 #ifdef GEM_DEBUG
1323 	if (sc->sc_debug)
1324 		printf("gem_mii_writereg: phy %d reg %d val %x\n",
1325 			phy, reg, val);
1326 #endif
1327 
1328 	/* Construct the frame command */
1329 	v = GEM_MIF_FRAME_WRITE			|
1330 	    (phy << GEM_MIF_PHY_SHIFT)		|
1331 	    (reg << GEM_MIF_REG_SHIFT)		|
1332 	    (val & GEM_MIF_FRAME_DATA);
1333 
1334 	bus_space_write_4(t, mif, GEM_MIF_FRAME, v);
1335 	for (n = 0; n < 100; n++) {
1336 		DELAY(1);
1337 		v = bus_space_read_4(t, mif, GEM_MIF_FRAME);
1338 		if (v & GEM_MIF_FRAME_TA0)
1339 			return;
1340 	}
1341 
1342 	printf("%s: mii_write timeout\n", sc->sc_dev.dv_xname);
1343 }
1344 
1345 void
1346 gem_mii_statchg(struct device *dev)
1347 {
1348 	struct gem_softc *sc = (void *)dev;
1349 #ifdef GEM_DEBUG
1350 	uint64_t instance = IFM_INST(sc->sc_mii.mii_media.ifm_cur->ifm_media);
1351 #endif
1352 	bus_space_tag_t t = sc->sc_bustag;
1353 	bus_space_handle_t mac = sc->sc_h1;
1354 	u_int32_t v;
1355 
1356 #ifdef GEM_DEBUG
1357 	if (sc->sc_debug)
1358 		printf("gem_mii_statchg: status change: phy = %lld\n", instance);
1359 #endif
1360 
1361 	/* Set tx full duplex options */
1362 	bus_space_write_4(t, mac, GEM_MAC_TX_CONFIG, 0);
1363 	delay(10000); /* reg must be cleared and delay before changing. */
1364 	v = GEM_MAC_TX_ENA_IPG0|GEM_MAC_TX_NGU|GEM_MAC_TX_NGU_LIMIT|
1365 		GEM_MAC_TX_ENABLE;
1366 	if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_FDX) != 0) {
1367 		v |= GEM_MAC_TX_IGN_CARRIER|GEM_MAC_TX_IGN_COLLIS;
1368 	}
1369 	bus_space_write_4(t, mac, GEM_MAC_TX_CONFIG, v);
1370 
1371 	/* XIF Configuration */
1372 	v = GEM_MAC_XIF_TX_MII_ENA;
1373 	v |= GEM_MAC_XIF_LINK_LED;
1374 
1375 	/* External MII needs echo disable if half duplex. */
1376 	if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_FDX) != 0)
1377 		/* turn on full duplex LED */
1378 		v |= GEM_MAC_XIF_FDPLX_LED;
1379 	else
1380 		/* half duplex -- disable echo */
1381 		v |= GEM_MAC_XIF_ECHO_DISABL;
1382 
1383 	switch (IFM_SUBTYPE(sc->sc_mii.mii_media_active)) {
1384 	case IFM_1000_T:  /* Gigabit using GMII interface */
1385 	case IFM_1000_SX:
1386 		v |= GEM_MAC_XIF_GMII_MODE;
1387 		break;
1388 	default:
1389 		v &= ~GEM_MAC_XIF_GMII_MODE;
1390 	}
1391 	bus_space_write_4(t, mac, GEM_MAC_XIF_CONFIG, v);
1392 
1393 	/*
1394 	 * 802.3x flow control
1395 	 */
1396 	v = bus_space_read_4(t, mac, GEM_MAC_CONTROL_CONFIG);
1397 	v &= ~(GEM_MAC_CC_RX_PAUSE | GEM_MAC_CC_TX_PAUSE);
1398 	if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_ETH_RXPAUSE) != 0)
1399 		v |= GEM_MAC_CC_RX_PAUSE;
1400 	if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_ETH_TXPAUSE) != 0)
1401 		v |= GEM_MAC_CC_TX_PAUSE;
1402 	bus_space_write_4(t, mac, GEM_MAC_CONTROL_CONFIG, v);
1403 }
1404 
1405 int
1406 gem_pcs_readreg(struct device *self, int phy, int reg)
1407 {
1408 	struct gem_softc *sc = (void *)self;
1409 	bus_space_tag_t t = sc->sc_bustag;
1410 	bus_space_handle_t pcs = sc->sc_h1;
1411 
1412 #ifdef GEM_DEBUG
1413 	if (sc->sc_debug)
1414 		printf("gem_pcs_readreg: phy %d reg %d\n", phy, reg);
1415 #endif
1416 
1417 	if (phy != GEM_PHYAD_EXTERNAL)
1418 		return (0);
1419 
1420 	switch (reg) {
1421 	case MII_BMCR:
1422 		reg = GEM_MII_CONTROL;
1423 		break;
1424 	case MII_BMSR:
1425 		reg = GEM_MII_STATUS;
1426 		break;
1427 	case MII_ANAR:
1428 		reg = GEM_MII_ANAR;
1429 		break;
1430 	case MII_ANLPAR:
1431 		reg = GEM_MII_ANLPAR;
1432 		break;
1433 	case MII_EXTSR:
1434 		return (EXTSR_1000XFDX|EXTSR_1000XHDX);
1435 	default:
1436 		return (0);
1437 	}
1438 
1439 	return bus_space_read_4(t, pcs, reg);
1440 }
1441 
1442 void
1443 gem_pcs_writereg(struct device *self, int phy, int reg, int val)
1444 {
1445 	struct gem_softc *sc = (void *)self;
1446 	bus_space_tag_t t = sc->sc_bustag;
1447 	bus_space_handle_t pcs = sc->sc_h1;
1448 	int reset = 0;
1449 
1450 #ifdef GEM_DEBUG
1451 	if (sc->sc_debug)
1452 		printf("gem_pcs_writereg: phy %d reg %d val %x\n",
1453 			phy, reg, val);
1454 #endif
1455 
1456 	if (phy != GEM_PHYAD_EXTERNAL)
1457 		return;
1458 
1459 	if (reg == MII_ANAR)
1460 		bus_space_write_4(t, pcs, GEM_MII_CONFIG, 0);
1461 
1462 	switch (reg) {
1463 	case MII_BMCR:
1464 		reset = (val & GEM_MII_CONTROL_RESET);
1465 		reg = GEM_MII_CONTROL;
1466 		break;
1467 	case MII_BMSR:
1468 		reg = GEM_MII_STATUS;
1469 		break;
1470 	case MII_ANAR:
1471 		reg = GEM_MII_ANAR;
1472 		break;
1473 	case MII_ANLPAR:
1474 		reg = GEM_MII_ANLPAR;
1475 		break;
1476 	default:
1477 		return;
1478 	}
1479 
1480 	bus_space_write_4(t, pcs, reg, val);
1481 
1482 	if (reset)
1483 		gem_bitwait(sc, pcs, GEM_MII_CONTROL, GEM_MII_CONTROL_RESET, 0);
1484 
1485 	if (reg == GEM_MII_ANAR || reset) {
1486 		bus_space_write_4(t, pcs, GEM_MII_SLINK_CONTROL,
1487 		    GEM_MII_SLINK_LOOPBACK|GEM_MII_SLINK_EN_SYNC_D);
1488 		bus_space_write_4(t, pcs, GEM_MII_CONFIG,
1489 		    GEM_MII_CONFIG_ENABLE);
1490 	}
1491 }
1492 
1493 int
1494 gem_mediachange(struct ifnet *ifp)
1495 {
1496 	struct gem_softc *sc = ifp->if_softc;
1497 	struct mii_data *mii = &sc->sc_mii;
1498 
1499 	if (mii->mii_instance) {
1500 		struct mii_softc *miisc;
1501 		LIST_FOREACH(miisc, &mii->mii_phys, mii_list)
1502 			mii_phy_reset(miisc);
1503 	}
1504 
1505 	return (mii_mediachg(&sc->sc_mii));
1506 }
1507 
1508 void
1509 gem_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
1510 {
1511 	struct gem_softc *sc = ifp->if_softc;
1512 
1513 	mii_pollstat(&sc->sc_mii);
1514 	ifmr->ifm_active = sc->sc_mii.mii_media_active;
1515 	ifmr->ifm_status = sc->sc_mii.mii_media_status;
1516 }
1517 
1518 /*
1519  * Process an ioctl request.
1520  */
1521 int
1522 gem_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1523 {
1524 	struct gem_softc *sc = ifp->if_softc;
1525 	struct ifreq *ifr = (struct ifreq *)data;
1526 	int s, error = 0;
1527 
1528 	s = splnet();
1529 
1530 	switch (cmd) {
1531 	case SIOCSIFADDR:
1532 		ifp->if_flags |= IFF_UP;
1533 		if ((ifp->if_flags & IFF_RUNNING) == 0)
1534 			gem_init(ifp);
1535 		break;
1536 
1537 	case SIOCSIFFLAGS:
1538 		if (ifp->if_flags & IFF_UP) {
1539 			if (ifp->if_flags & IFF_RUNNING)
1540 				error = ENETRESET;
1541 			else
1542 				gem_init(ifp);
1543 		} else {
1544 			if (ifp->if_flags & IFF_RUNNING)
1545 				gem_stop(ifp, 0);
1546 		}
1547 #ifdef GEM_DEBUG
1548 		sc->sc_debug = (ifp->if_flags & IFF_DEBUG) != 0 ? 1 : 0;
1549 #endif
1550 		break;
1551 
1552 	case SIOCGIFMEDIA:
1553 	case SIOCSIFMEDIA:
1554 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd);
1555 		break;
1556 
1557 	case SIOCGIFRXR:
1558 		error = if_rxr_ioctl((struct if_rxrinfo *)ifr->ifr_data,
1559 		    NULL, MCLBYTES, &sc->sc_rx_ring);
1560 		break;
1561 
1562 	default:
1563 		error = ether_ioctl(ifp, &sc->sc_arpcom, cmd, data);
1564 	}
1565 
1566 	if (error == ENETRESET) {
1567 		if (ifp->if_flags & IFF_RUNNING)
1568 			gem_iff(sc);
1569 		error = 0;
1570 	}
1571 
1572 	splx(s);
1573 	return (error);
1574 }
1575 
1576 void
1577 gem_iff(struct gem_softc *sc)
1578 {
1579 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
1580 	struct arpcom *ac = &sc->sc_arpcom;
1581 	struct ether_multi *enm;
1582 	struct ether_multistep step;
1583 	bus_space_tag_t t = sc->sc_bustag;
1584 	bus_space_handle_t h = sc->sc_h1;
1585 	u_int32_t crc, hash[16], rxcfg;
1586 	int i;
1587 
1588 	rxcfg = bus_space_read_4(t, h, GEM_MAC_RX_CONFIG);
1589 	rxcfg &= ~(GEM_MAC_RX_HASH_FILTER | GEM_MAC_RX_PROMISCUOUS |
1590 	    GEM_MAC_RX_PROMISC_GRP);
1591 	ifp->if_flags &= ~IFF_ALLMULTI;
1592 
1593 	if (ifp->if_flags & IFF_PROMISC || ac->ac_multirangecnt > 0) {
1594 		ifp->if_flags |= IFF_ALLMULTI;
1595 		if (ifp->if_flags & IFF_PROMISC)
1596 			rxcfg |= GEM_MAC_RX_PROMISCUOUS;
1597 		else
1598 			rxcfg |= GEM_MAC_RX_PROMISC_GRP;
1599 	} else {
1600 		/*
1601 		 * Set up multicast address filter by passing all multicast
1602 		 * addresses through a crc generator, and then using the
1603 		 * high order 8 bits as an index into the 256 bit logical
1604 		 * address filter.  The high order 4 bits selects the word,
1605 		 * while the other 4 bits select the bit within the word
1606 		 * (where bit 0 is the MSB).
1607 		 */
1608 
1609 		rxcfg |= GEM_MAC_RX_HASH_FILTER;
1610 
1611 		/* Clear hash table */
1612 		for (i = 0; i < 16; i++)
1613 			hash[i] = 0;
1614 
1615 		ETHER_FIRST_MULTI(step, ac, enm);
1616 		while (enm != NULL) {
1617 			crc = ether_crc32_le(enm->enm_addrlo,
1618 			    ETHER_ADDR_LEN);
1619 
1620 			/* Just want the 8 most significant bits. */
1621 			crc >>= 24;
1622 
1623 			/* Set the corresponding bit in the filter. */
1624 			hash[crc >> 4] |= 1 << (15 - (crc & 15));
1625 
1626 			ETHER_NEXT_MULTI(step, enm);
1627 		}
1628 
1629 		/* Now load the hash table into the chip (if we are using it) */
1630 		for (i = 0; i < 16; i++) {
1631 			bus_space_write_4(t, h,
1632 			    GEM_MAC_HASH0 + i * (GEM_MAC_HASH1 - GEM_MAC_HASH0),
1633 			    hash[i]);
1634 		}
1635 	}
1636 
1637 	bus_space_write_4(t, h, GEM_MAC_RX_CONFIG, rxcfg);
1638 }
1639 
1640 /*
1641  * Transmit interrupt.
1642  */
1643 int
1644 gem_tint(struct gem_softc *sc, u_int32_t status)
1645 {
1646 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
1647 	struct gem_sxd *sd;
1648 	u_int32_t cons, prod;
1649 	int free = 0;
1650 
1651 	prod = status >> 19;
1652 	cons = sc->sc_tx_cons;
1653 	while (cons != prod) {
1654 		sd = &sc->sc_txd[cons];
1655 		if (sd->sd_mbuf != NULL) {
1656 			bus_dmamap_sync(sc->sc_dmatag, sd->sd_map, 0,
1657 			    sd->sd_map->dm_mapsize, BUS_DMASYNC_POSTWRITE);
1658 			bus_dmamap_unload(sc->sc_dmatag, sd->sd_map);
1659 			m_freem(sd->sd_mbuf);
1660 			sd->sd_mbuf = NULL;
1661 		}
1662 
1663 		free = 1;
1664 
1665 		cons++;
1666 		cons &= GEM_NTXDESC - 1;
1667 	}
1668 
1669 	if (free == 0)
1670 		return (0);
1671 
1672 	sc->sc_tx_cons = cons;
1673 
1674 	if (sc->sc_tx_prod == cons)
1675 		ifp->if_timer = 0;
1676 
1677 	if (ifq_is_oactive(&ifp->if_snd))
1678 		ifq_restart(&ifp->if_snd);
1679 
1680 	return (1);
1681 }
1682 
1683 int
1684 gem_load_mbuf(struct gem_softc *sc, struct gem_sxd *sd, struct mbuf *m)
1685 {
1686 	int error;
1687 
1688 	error = bus_dmamap_load_mbuf(sc->sc_dmatag, sd->sd_map, m,
1689 	    BUS_DMA_NOWAIT);
1690 	switch (error) {
1691 	case 0:
1692 		break;
1693 
1694 	case EFBIG: /* mbuf chain is too fragmented */
1695 		if (m_defrag(m, M_DONTWAIT) == 0 &&
1696 		    bus_dmamap_load_mbuf(sc->sc_dmatag, sd->sd_map, m,
1697 		    BUS_DMA_NOWAIT) == 0)
1698 		    	break;
1699 		/* FALLTHROUGH */
1700 	default:
1701 		return (1);
1702 	}
1703 
1704 	return (0);
1705 }
1706 
1707 void
1708 gem_start(struct ifqueue *ifq)
1709 {
1710 	struct ifnet *ifp = ifq->ifq_if;
1711 	struct gem_softc *sc = ifp->if_softc;
1712 	struct gem_sxd *sd;
1713 	struct mbuf *m;
1714 	uint64_t flags, nflags;
1715 	bus_dmamap_t map;
1716 	uint32_t prod;
1717 	uint32_t free, used = 0;
1718 	uint32_t first, last;
1719 	int i;
1720 
1721 	prod = sc->sc_tx_prod;
1722 
1723 	/* figure out space */
1724 	free = sc->sc_tx_cons;
1725 	if (free <= prod)
1726 		free += GEM_NTXDESC;
1727 	free -= prod;
1728 
1729 	bus_dmamap_sync(sc->sc_dmatag, sc->sc_cddmamap,
1730 	    0, sizeof(struct gem_desc) * GEM_NTXDESC,
1731 	    BUS_DMASYNC_PREWRITE);
1732 
1733 	for (;;) {
1734 		if (used + GEM_NTXSEGS + 1 > free) {
1735 			ifq_set_oactive(&ifp->if_snd);
1736 			break;
1737 		}
1738 
1739 		m = ifq_dequeue(ifq);
1740 		if (m == NULL)
1741 			break;
1742 
1743 		first = prod;
1744 		sd = &sc->sc_txd[first];
1745 		map = sd->sd_map;
1746 
1747 		if (gem_load_mbuf(sc, sd, m)) {
1748 			m_freem(m);
1749 			ifp->if_oerrors++;
1750 			continue;
1751 		}
1752 
1753 #if NBPFILTER > 0
1754 		if (ifp->if_bpf)
1755 			bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_OUT);
1756 #endif
1757 
1758 		bus_dmamap_sync(sc->sc_dmatag, map, 0, map->dm_mapsize,
1759 		    BUS_DMASYNC_PREWRITE);
1760 
1761 		nflags = GEM_TD_START_OF_PACKET;
1762 		for (i = 0; i < map->dm_nsegs; i++) {
1763 			flags = nflags |
1764 			    (map->dm_segs[i].ds_len & GEM_TD_BUFSIZE);
1765 
1766 			GEM_DMA_WRITE(sc, &sc->sc_txdescs[prod].gd_addr,
1767 			    map->dm_segs[i].ds_addr);
1768 			GEM_DMA_WRITE(sc, &sc->sc_txdescs[prod].gd_flags,
1769 			    flags);
1770 
1771 			last = prod;
1772 			prod++;
1773 			prod &= GEM_NTXDESC - 1;
1774 
1775 			nflags = 0;
1776 		}
1777 		GEM_DMA_WRITE(sc, &sc->sc_txdescs[last].gd_flags,
1778 		    GEM_TD_END_OF_PACKET | flags);
1779 
1780 		used += map->dm_nsegs;
1781 		sc->sc_txd[last].sd_mbuf = m;
1782 		sc->sc_txd[first].sd_map = sc->sc_txd[last].sd_map;
1783 		sc->sc_txd[last].sd_map = map;
1784 	}
1785 
1786 	bus_dmamap_sync(sc->sc_dmatag, sc->sc_cddmamap,
1787 	    0, sizeof(struct gem_desc) * GEM_NTXDESC,
1788 	    BUS_DMASYNC_POSTWRITE);
1789 
1790 	if (used == 0)
1791 		return;
1792 
1793 	/* Commit. */
1794 	sc->sc_tx_prod = prod;
1795 
1796 	/* Transmit. */
1797 	bus_space_write_4(sc->sc_bustag, sc->sc_h1, GEM_TX_KICK, prod);
1798 
1799 	/* Set timeout in case hardware has problems transmitting. */
1800 	ifp->if_timer = 5;
1801 }
1802