xref: /freebsd/sys/dev/gem/if_gem.c (revision 66e576525d35c68fcb86f142ebaa5a448555c0c7)
1 /*-
2  * Copyright (C) 2001 Eduardo Horvath.
3  * Copyright (c) 2001-2003 Thomas Moestl
4  * Copyright (c) 2007 Marius Strobl <marius@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR  ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR  BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  *	from: NetBSD: gem.c,v 1.21 2002/06/01 23:50:58 lukem Exp
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 /*
35  * Driver for Apple GMAC, Sun ERI and Sun GEM Ethernet controllers
36  */
37 
38 #if 0
39 #define	GEM_DEBUG
40 #endif
41 
42 #if 0	/* XXX: In case of emergency, re-enable this. */
43 #define	GEM_RINT_TIMEOUT
44 #endif
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/bus.h>
49 #include <sys/callout.h>
50 #include <sys/endian.h>
51 #include <sys/mbuf.h>
52 #include <sys/malloc.h>
53 #include <sys/kernel.h>
54 #include <sys/lock.h>
55 #include <sys/module.h>
56 #include <sys/mutex.h>
57 #include <sys/socket.h>
58 #include <sys/sockio.h>
59 #include <sys/rman.h>
60 
61 #include <net/bpf.h>
62 #include <net/ethernet.h>
63 #include <net/if.h>
64 #include <net/if_arp.h>
65 #include <net/if_dl.h>
66 #include <net/if_media.h>
67 #include <net/if_types.h>
68 #include <net/if_vlan_var.h>
69 
70 #include <netinet/in.h>
71 #include <netinet/in_systm.h>
72 #include <netinet/ip.h>
73 #include <netinet/tcp.h>
74 #include <netinet/udp.h>
75 
76 #include <machine/bus.h>
77 
78 #include <dev/mii/mii.h>
79 #include <dev/mii/miivar.h>
80 
81 #include <dev/gem/if_gemreg.h>
82 #include <dev/gem/if_gemvar.h>
83 
84 CTASSERT(powerof2(GEM_NRXDESC) && GEM_NRXDESC >= 32 && GEM_NRXDESC <= 8192);
85 CTASSERT(powerof2(GEM_NTXDESC) && GEM_NTXDESC >= 32 && GEM_NTXDESC <= 8192);
86 
87 #define	GEM_TRIES	10000
88 
89 /*
90  * The hardware supports basic TCP/UDP checksum offloading.  However,
91  * the hardware doesn't compensate the checksum for UDP datagram which
92  * can yield to 0x0.  As a safe guard, UDP checksum offload is disabled
93  * by default.  It can be reactivated by setting special link option
94  * link0 with ifconfig(8).
95  */
96 #define	GEM_CSUM_FEATURES	(CSUM_TCP)
97 
98 static int	gem_add_rxbuf(struct gem_softc *sc, int idx);
99 static int	gem_bitwait(struct gem_softc *sc, u_int bank, bus_addr_t r,
100 		    uint32_t clr, uint32_t set);
101 static void	gem_cddma_callback(void *xsc, bus_dma_segment_t *segs,
102 		    int nsegs, int error);
103 static int	gem_disable_rx(struct gem_softc *sc);
104 static int	gem_disable_tx(struct gem_softc *sc);
105 static void	gem_eint(struct gem_softc *sc, u_int status);
106 static void	gem_init(void *xsc);
107 static void	gem_init_locked(struct gem_softc *sc);
108 static void	gem_init_regs(struct gem_softc *sc);
109 static int	gem_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
110 static int	gem_load_txmbuf(struct gem_softc *sc, struct mbuf **m_head);
111 static int	gem_meminit(struct gem_softc *sc);
112 static void	gem_mifinit(struct gem_softc *sc);
113 static void	gem_reset(struct gem_softc *sc);
114 static int	gem_reset_rx(struct gem_softc *sc);
115 static void	gem_reset_rxdma(struct gem_softc *sc);
116 static int	gem_reset_tx(struct gem_softc *sc);
117 static u_int	gem_ringsize(u_int sz);
118 static void	gem_rint(struct gem_softc *sc);
119 #ifdef GEM_RINT_TIMEOUT
120 static void	gem_rint_timeout(void *arg);
121 #endif
122 static inline void gem_rxcksum(struct mbuf *m, uint64_t flags);
123 static void	gem_rxdrain(struct gem_softc *sc);
124 static void	gem_setladrf(struct gem_softc *sc);
125 static void	gem_start(struct ifnet *ifp);
126 static void	gem_start_locked(struct ifnet *ifp);
127 static void	gem_stop(struct ifnet *ifp, int disable);
128 static void	gem_tick(void *arg);
129 static void	gem_tint(struct gem_softc *sc);
130 static inline void gem_txkick(struct gem_softc *sc);
131 static int	gem_watchdog(struct gem_softc *sc);
132 
133 devclass_t gem_devclass;
134 DRIVER_MODULE(miibus, gem, miibus_driver, miibus_devclass, 0, 0);
135 MODULE_DEPEND(gem, miibus, 1, 1, 1);
136 
137 #ifdef GEM_DEBUG
138 #include <sys/ktr.h>
139 #define	KTR_GEM		KTR_SPARE2
140 #endif
141 
142 #define	GEM_BANK1_BITWAIT(sc, r, clr, set)				\
143 	gem_bitwait((sc), GEM_RES_BANK1, (r), (clr), (set))
144 #define	GEM_BANK2_BITWAIT(sc, r, clr, set)				\
145 	gem_bitwait((sc), GEM_RES_BANK2, (r), (clr), (set))
146 
147 int
148 gem_attach(struct gem_softc *sc)
149 {
150 	struct gem_txsoft *txs;
151 	struct ifnet *ifp;
152 	int error, i;
153 	uint32_t v;
154 
155 	if (bootverbose)
156 		device_printf(sc->sc_dev, "flags=0x%x\n", sc->sc_flags);
157 
158 	/* Set up ifnet structure. */
159 	ifp = sc->sc_ifp = if_alloc(IFT_ETHER);
160 	if (ifp == NULL)
161 		return (ENOSPC);
162 	sc->sc_csum_features = GEM_CSUM_FEATURES;
163 	ifp->if_softc = sc;
164 	if_initname(ifp, device_get_name(sc->sc_dev),
165 	    device_get_unit(sc->sc_dev));
166 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
167 	ifp->if_start = gem_start;
168 	ifp->if_ioctl = gem_ioctl;
169 	ifp->if_init = gem_init;
170 	IFQ_SET_MAXLEN(&ifp->if_snd, GEM_TXQUEUELEN);
171 	ifp->if_snd.ifq_drv_maxlen = GEM_TXQUEUELEN;
172 	IFQ_SET_READY(&ifp->if_snd);
173 
174 	callout_init_mtx(&sc->sc_tick_ch, &sc->sc_mtx, 0);
175 #ifdef GEM_RINT_TIMEOUT
176 	callout_init_mtx(&sc->sc_rx_ch, &sc->sc_mtx, 0);
177 #endif
178 
179 	/* Make sure the chip is stopped. */
180 	gem_reset(sc);
181 
182 	error = bus_dma_tag_create(bus_get_dma_tag(sc->sc_dev), 1, 0,
183 	    BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
184 	    BUS_SPACE_MAXSIZE_32BIT, 0, BUS_SPACE_MAXSIZE_32BIT, 0, NULL,
185 	    NULL, &sc->sc_pdmatag);
186 	if (error != 0)
187 		goto fail_ifnet;
188 
189 	error = bus_dma_tag_create(sc->sc_pdmatag, 1, 0,
190 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL, MCLBYTES,
191 	    1, MCLBYTES, BUS_DMA_ALLOCNOW, NULL, NULL, &sc->sc_rdmatag);
192 	if (error != 0)
193 		goto fail_ptag;
194 
195 	error = bus_dma_tag_create(sc->sc_pdmatag, 1, 0,
196 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
197 	    MCLBYTES * GEM_NTXSEGS, GEM_NTXSEGS, MCLBYTES,
198 	    BUS_DMA_ALLOCNOW, NULL, NULL, &sc->sc_tdmatag);
199 	if (error != 0)
200 		goto fail_rtag;
201 
202 	error = bus_dma_tag_create(sc->sc_pdmatag, PAGE_SIZE, 0,
203 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
204 	    sizeof(struct gem_control_data), 1,
205 	    sizeof(struct gem_control_data), 0,
206 	    NULL, NULL, &sc->sc_cdmatag);
207 	if (error != 0)
208 		goto fail_ttag;
209 
210 	/*
211 	 * Allocate the control data structures, create and load the
212 	 * DMA map for it.
213 	 */
214 	if ((error = bus_dmamem_alloc(sc->sc_cdmatag,
215 	    (void **)&sc->sc_control_data,
216 	    BUS_DMA_WAITOK | BUS_DMA_COHERENT | BUS_DMA_ZERO,
217 	    &sc->sc_cddmamap)) != 0) {
218 		device_printf(sc->sc_dev,
219 		    "unable to allocate control data, error = %d\n", error);
220 		goto fail_ctag;
221 	}
222 
223 	sc->sc_cddma = 0;
224 	if ((error = bus_dmamap_load(sc->sc_cdmatag, sc->sc_cddmamap,
225 	    sc->sc_control_data, sizeof(struct gem_control_data),
226 	    gem_cddma_callback, sc, 0)) != 0 || sc->sc_cddma == 0) {
227 		device_printf(sc->sc_dev,
228 		    "unable to load control data DMA map, error = %d\n",
229 		    error);
230 		goto fail_cmem;
231 	}
232 
233 	/*
234 	 * Initialize the transmit job descriptors.
235 	 */
236 	STAILQ_INIT(&sc->sc_txfreeq);
237 	STAILQ_INIT(&sc->sc_txdirtyq);
238 
239 	/*
240 	 * Create the transmit buffer DMA maps.
241 	 */
242 	error = ENOMEM;
243 	for (i = 0; i < GEM_TXQUEUELEN; i++) {
244 		txs = &sc->sc_txsoft[i];
245 		txs->txs_mbuf = NULL;
246 		txs->txs_ndescs = 0;
247 		if ((error = bus_dmamap_create(sc->sc_tdmatag, 0,
248 		    &txs->txs_dmamap)) != 0) {
249 			device_printf(sc->sc_dev,
250 			    "unable to create TX DMA map %d, error = %d\n",
251 			    i, error);
252 			goto fail_txd;
253 		}
254 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
255 	}
256 
257 	/*
258 	 * Create the receive buffer DMA maps.
259 	 */
260 	for (i = 0; i < GEM_NRXDESC; i++) {
261 		if ((error = bus_dmamap_create(sc->sc_rdmatag, 0,
262 		    &sc->sc_rxsoft[i].rxs_dmamap)) != 0) {
263 			device_printf(sc->sc_dev,
264 			    "unable to create RX DMA map %d, error = %d\n",
265 			    i, error);
266 			goto fail_rxd;
267 		}
268 		sc->sc_rxsoft[i].rxs_mbuf = NULL;
269 	}
270 
271 	/* Bypass probing PHYs if we already know for sure to use a SERDES. */
272 	if ((sc->sc_flags & GEM_SERDES) != 0)
273 		goto serdes;
274 
275 	/* Bad things will happen when touching this register on ERI. */
276 	if (sc->sc_variant != GEM_SUN_ERI) {
277 		GEM_BANK1_WRITE_4(sc, GEM_MII_DATAPATH_MODE,
278 		    GEM_MII_DATAPATH_MII);
279 		GEM_BANK1_BARRIER(sc, GEM_MII_DATAPATH_MODE, 4,
280 		    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
281 	}
282 
283 	gem_mifinit(sc);
284 
285 	/*
286 	 * Look for an external PHY.
287 	 */
288 	error = ENXIO;
289 	v = GEM_BANK1_READ_4(sc, GEM_MIF_CONFIG);
290 	if ((v & GEM_MIF_CONFIG_MDI1) != 0) {
291 		v |= GEM_MIF_CONFIG_PHY_SEL;
292 		GEM_BANK1_WRITE_4(sc, GEM_MIF_CONFIG, v);
293 		GEM_BANK1_BARRIER(sc, GEM_MIF_CONFIG, 4,
294 		    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
295 		switch (sc->sc_variant) {
296 		case GEM_SUN_ERI:
297 			sc->sc_phyad = GEM_PHYAD_EXTERNAL;
298 			break;
299 		default:
300 			sc->sc_phyad = -1;
301 			break;
302 		}
303 		error = mii_phy_probe(sc->sc_dev, &sc->sc_miibus,
304 		    gem_mediachange, gem_mediastatus);
305 	}
306 
307 	/*
308 	 * Fall back on an internal PHY if no external PHY was found.
309 	 * Note that with Apple (K2) GMACs GEM_MIF_CONFIG_MDI0 can't be
310 	 * trusted when the firmware has powered down the chip.
311 	 */
312 	if (error != 0 &&
313 	    ((v & GEM_MIF_CONFIG_MDI0) != 0 || GEM_IS_APPLE(sc))) {
314 		v &= ~GEM_MIF_CONFIG_PHY_SEL;
315 		GEM_BANK1_WRITE_4(sc, GEM_MIF_CONFIG, v);
316 		GEM_BANK1_BARRIER(sc, GEM_MIF_CONFIG, 4,
317 		    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
318 		switch (sc->sc_variant) {
319 		case GEM_SUN_ERI:
320 		case GEM_APPLE_K2_GMAC:
321 			sc->sc_phyad = GEM_PHYAD_INTERNAL;
322 			break;
323 		case GEM_APPLE_GMAC:
324 			sc->sc_phyad = GEM_PHYAD_EXTERNAL;
325 			break;
326 		default:
327 			sc->sc_phyad = -1;
328 			break;
329 		}
330 		error = mii_phy_probe(sc->sc_dev, &sc->sc_miibus,
331 		    gem_mediachange, gem_mediastatus);
332 	}
333 
334 	/*
335 	 * Try the external PCS SERDES if we didn't find any PHYs.
336 	 */
337 	if (error != 0 && sc->sc_variant == GEM_SUN_GEM) {
338  serdes:
339 		GEM_BANK1_WRITE_4(sc, GEM_MII_DATAPATH_MODE,
340 		    GEM_MII_DATAPATH_SERDES);
341 		GEM_BANK1_BARRIER(sc, GEM_MII_DATAPATH_MODE, 4,
342 		    BUS_SPACE_BARRIER_WRITE);
343 		GEM_BANK1_WRITE_4(sc, GEM_MII_SLINK_CONTROL,
344 		    GEM_MII_SLINK_LOOPBACK | GEM_MII_SLINK_EN_SYNC_D);
345 		GEM_BANK1_BARRIER(sc, GEM_MII_SLINK_CONTROL, 4,
346 		    BUS_SPACE_BARRIER_WRITE);
347 		GEM_BANK1_WRITE_4(sc, GEM_MII_CONFIG, GEM_MII_CONFIG_ENABLE);
348 		GEM_BANK1_BARRIER(sc, GEM_MII_CONFIG, 4,
349 		    BUS_SPACE_BARRIER_WRITE);
350 		sc->sc_flags |= GEM_SERDES;
351 		sc->sc_phyad = GEM_PHYAD_EXTERNAL;
352 		error = mii_phy_probe(sc->sc_dev, &sc->sc_miibus,
353 		    gem_mediachange, gem_mediastatus);
354 	}
355 	if (error != 0) {
356 		device_printf(sc->sc_dev, "PHY probe failed: %d\n", error);
357 		goto fail_rxd;
358 	}
359 	sc->sc_mii = device_get_softc(sc->sc_miibus);
360 
361 	/*
362 	 * From this point forward, the attachment cannot fail.  A failure
363 	 * before this point releases all resources that may have been
364 	 * allocated.
365 	 */
366 
367 	/* Get RX FIFO size. */
368 	sc->sc_rxfifosize = 64 *
369 	    GEM_BANK1_READ_4(sc, GEM_RX_FIFO_SIZE);
370 
371 	/* Get TX FIFO size. */
372 	v = GEM_BANK1_READ_4(sc, GEM_TX_FIFO_SIZE);
373 	device_printf(sc->sc_dev, "%ukB RX FIFO, %ukB TX FIFO\n",
374 	    sc->sc_rxfifosize / 1024, v / 16);
375 
376 	/* Attach the interface. */
377 	ether_ifattach(ifp, sc->sc_enaddr);
378 
379 	/*
380 	 * Tell the upper layer(s) we support long frames/checksum offloads.
381 	 */
382 	ifp->if_data.ifi_hdrlen = sizeof(struct ether_vlan_header);
383 	ifp->if_capabilities |= IFCAP_VLAN_MTU | IFCAP_HWCSUM;
384 	ifp->if_hwassist |= sc->sc_csum_features;
385 	ifp->if_capenable |= IFCAP_VLAN_MTU | IFCAP_HWCSUM;
386 
387 	return (0);
388 
389 	/*
390 	 * Free any resources we've allocated during the failed attach
391 	 * attempt.  Do this in reverse order and fall through.
392 	 */
393  fail_rxd:
394 	for (i = 0; i < GEM_NRXDESC; i++)
395 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
396 			bus_dmamap_destroy(sc->sc_rdmatag,
397 			    sc->sc_rxsoft[i].rxs_dmamap);
398  fail_txd:
399 	for (i = 0; i < GEM_TXQUEUELEN; i++)
400 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
401 			bus_dmamap_destroy(sc->sc_tdmatag,
402 			    sc->sc_txsoft[i].txs_dmamap);
403 	bus_dmamap_unload(sc->sc_cdmatag, sc->sc_cddmamap);
404  fail_cmem:
405 	bus_dmamem_free(sc->sc_cdmatag, sc->sc_control_data,
406 	    sc->sc_cddmamap);
407  fail_ctag:
408 	bus_dma_tag_destroy(sc->sc_cdmatag);
409  fail_ttag:
410 	bus_dma_tag_destroy(sc->sc_tdmatag);
411  fail_rtag:
412 	bus_dma_tag_destroy(sc->sc_rdmatag);
413  fail_ptag:
414 	bus_dma_tag_destroy(sc->sc_pdmatag);
415  fail_ifnet:
416 	if_free(ifp);
417 	return (error);
418 }
419 
420 void
421 gem_detach(struct gem_softc *sc)
422 {
423 	struct ifnet *ifp = sc->sc_ifp;
424 	int i;
425 
426 	ether_ifdetach(ifp);
427 	GEM_LOCK(sc);
428 	gem_stop(ifp, 1);
429 	GEM_UNLOCK(sc);
430 	callout_drain(&sc->sc_tick_ch);
431 #ifdef GEM_RINT_TIMEOUT
432 	callout_drain(&sc->sc_rx_ch);
433 #endif
434 	if_free(ifp);
435 	device_delete_child(sc->sc_dev, sc->sc_miibus);
436 
437 	for (i = 0; i < GEM_NRXDESC; i++)
438 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
439 			bus_dmamap_destroy(sc->sc_rdmatag,
440 			    sc->sc_rxsoft[i].rxs_dmamap);
441 	for (i = 0; i < GEM_TXQUEUELEN; i++)
442 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
443 			bus_dmamap_destroy(sc->sc_tdmatag,
444 			    sc->sc_txsoft[i].txs_dmamap);
445 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
446 	bus_dmamap_unload(sc->sc_cdmatag, sc->sc_cddmamap);
447 	bus_dmamem_free(sc->sc_cdmatag, sc->sc_control_data,
448 	    sc->sc_cddmamap);
449 	bus_dma_tag_destroy(sc->sc_cdmatag);
450 	bus_dma_tag_destroy(sc->sc_tdmatag);
451 	bus_dma_tag_destroy(sc->sc_rdmatag);
452 	bus_dma_tag_destroy(sc->sc_pdmatag);
453 }
454 
455 void
456 gem_suspend(struct gem_softc *sc)
457 {
458 	struct ifnet *ifp = sc->sc_ifp;
459 
460 	GEM_LOCK(sc);
461 	gem_stop(ifp, 0);
462 	GEM_UNLOCK(sc);
463 }
464 
465 void
466 gem_resume(struct gem_softc *sc)
467 {
468 	struct ifnet *ifp = sc->sc_ifp;
469 
470 	GEM_LOCK(sc);
471 	/*
472 	 * On resume all registers have to be initialized again like
473 	 * after power-on.
474 	 */
475 	sc->sc_flags &= ~GEM_INITED;
476 	if (ifp->if_flags & IFF_UP)
477 		gem_init_locked(sc);
478 	GEM_UNLOCK(sc);
479 }
480 
481 static inline void
482 gem_rxcksum(struct mbuf *m, uint64_t flags)
483 {
484 	struct ether_header *eh;
485 	struct ip *ip;
486 	struct udphdr *uh;
487 	uint16_t *opts;
488 	int32_t hlen, len, pktlen;
489 	uint32_t temp32;
490 	uint16_t cksum;
491 
492 	pktlen = m->m_pkthdr.len;
493 	if (pktlen < sizeof(struct ether_header) + sizeof(struct ip))
494 		return;
495 	eh = mtod(m, struct ether_header *);
496 	if (eh->ether_type != htons(ETHERTYPE_IP))
497 		return;
498 	ip = (struct ip *)(eh + 1);
499 	if (ip->ip_v != IPVERSION)
500 		return;
501 
502 	hlen = ip->ip_hl << 2;
503 	pktlen -= sizeof(struct ether_header);
504 	if (hlen < sizeof(struct ip))
505 		return;
506 	if (ntohs(ip->ip_len) < hlen)
507 		return;
508 	if (ntohs(ip->ip_len) != pktlen)
509 		return;
510 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK))
511 		return;	/* Cannot handle fragmented packet. */
512 
513 	switch (ip->ip_p) {
514 	case IPPROTO_TCP:
515 		if (pktlen < (hlen + sizeof(struct tcphdr)))
516 			return;
517 		break;
518 	case IPPROTO_UDP:
519 		if (pktlen < (hlen + sizeof(struct udphdr)))
520 			return;
521 		uh = (struct udphdr *)((uint8_t *)ip + hlen);
522 		if (uh->uh_sum == 0)
523 			return; /* no checksum */
524 		break;
525 	default:
526 		return;
527 	}
528 
529 	cksum = ~(flags & GEM_RD_CHECKSUM);
530 	/* checksum fixup for IP options */
531 	len = hlen - sizeof(struct ip);
532 	if (len > 0) {
533 		opts = (uint16_t *)(ip + 1);
534 		for (; len > 0; len -= sizeof(uint16_t), opts++) {
535 			temp32 = cksum - *opts;
536 			temp32 = (temp32 >> 16) + (temp32 & 65535);
537 			cksum = temp32 & 65535;
538 		}
539 	}
540 	m->m_pkthdr.csum_flags |= CSUM_DATA_VALID;
541 	m->m_pkthdr.csum_data = cksum;
542 }
543 
544 static void
545 gem_cddma_callback(void *xsc, bus_dma_segment_t *segs, int nsegs, int error)
546 {
547 	struct gem_softc *sc = xsc;
548 
549 	if (error != 0)
550 		return;
551 	if (nsegs != 1)
552 		panic("%s: bad control buffer segment count", __func__);
553 	sc->sc_cddma = segs[0].ds_addr;
554 }
555 
556 static void
557 gem_tick(void *arg)
558 {
559 	struct gem_softc *sc = arg;
560 	struct ifnet *ifp = sc->sc_ifp;
561 	uint32_t v;
562 
563 	GEM_LOCK_ASSERT(sc, MA_OWNED);
564 
565 	/*
566 	 * Unload collision and error counters.
567 	 */
568 	ifp->if_collisions +=
569 	    GEM_BANK1_READ_4(sc, GEM_MAC_NORM_COLL_CNT) +
570 	    GEM_BANK1_READ_4(sc, GEM_MAC_FIRST_COLL_CNT);
571 	v = GEM_BANK1_READ_4(sc, GEM_MAC_EXCESS_COLL_CNT) +
572 	    GEM_BANK1_READ_4(sc, GEM_MAC_LATE_COLL_CNT);
573 	ifp->if_collisions += v;
574 	ifp->if_oerrors += v;
575 	ifp->if_ierrors +=
576 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_LEN_ERR_CNT) +
577 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_ALIGN_ERR) +
578 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CRC_ERR_CNT) +
579 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CODE_VIOL);
580 
581 	/*
582 	 * Then clear the hardware counters.
583 	 */
584 	GEM_BANK1_WRITE_4(sc, GEM_MAC_NORM_COLL_CNT, 0);
585 	GEM_BANK1_WRITE_4(sc, GEM_MAC_FIRST_COLL_CNT, 0);
586 	GEM_BANK1_WRITE_4(sc, GEM_MAC_EXCESS_COLL_CNT, 0);
587 	GEM_BANK1_WRITE_4(sc, GEM_MAC_LATE_COLL_CNT, 0);
588 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_LEN_ERR_CNT, 0);
589 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_ALIGN_ERR, 0);
590 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CRC_ERR_CNT, 0);
591 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CODE_VIOL, 0);
592 
593 	mii_tick(sc->sc_mii);
594 
595 	if (gem_watchdog(sc) == EJUSTRETURN)
596 		return;
597 
598 	callout_reset(&sc->sc_tick_ch, hz, gem_tick, sc);
599 }
600 
601 static int
602 gem_bitwait(struct gem_softc *sc, u_int bank, bus_addr_t r, uint32_t clr,
603     uint32_t set)
604 {
605 	int i;
606 	uint32_t reg;
607 
608 	for (i = GEM_TRIES; i--; DELAY(100)) {
609 		reg = GEM_BANKN_READ_M(bank, 4, sc, r);
610 		if ((reg & clr) == 0 && (reg & set) == set)
611 			return (1);
612 	}
613 	return (0);
614 }
615 
616 static void
617 gem_reset(struct gem_softc *sc)
618 {
619 
620 #ifdef GEM_DEBUG
621 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
622 #endif
623 	gem_reset_rx(sc);
624 	gem_reset_tx(sc);
625 
626 	/* Do a full reset. */
627 	GEM_BANK2_WRITE_4(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX);
628 	GEM_BANK2_BARRIER(sc, GEM_RESET, 4,
629 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
630 	if (!GEM_BANK2_BITWAIT(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX, 0))
631 		device_printf(sc->sc_dev, "cannot reset device\n");
632 }
633 
634 static void
635 gem_rxdrain(struct gem_softc *sc)
636 {
637 	struct gem_rxsoft *rxs;
638 	int i;
639 
640 	for (i = 0; i < GEM_NRXDESC; i++) {
641 		rxs = &sc->sc_rxsoft[i];
642 		if (rxs->rxs_mbuf != NULL) {
643 			bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
644 			    BUS_DMASYNC_POSTREAD);
645 			bus_dmamap_unload(sc->sc_rdmatag, rxs->rxs_dmamap);
646 			m_freem(rxs->rxs_mbuf);
647 			rxs->rxs_mbuf = NULL;
648 		}
649 	}
650 }
651 
652 static void
653 gem_stop(struct ifnet *ifp, int disable)
654 {
655 	struct gem_softc *sc = ifp->if_softc;
656 	struct gem_txsoft *txs;
657 
658 #ifdef GEM_DEBUG
659 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
660 #endif
661 
662 	callout_stop(&sc->sc_tick_ch);
663 #ifdef GEM_RINT_TIMEOUT
664 	callout_stop(&sc->sc_rx_ch);
665 #endif
666 
667 	gem_reset_tx(sc);
668 	gem_reset_rx(sc);
669 
670 	/*
671 	 * Release any queued transmit buffers.
672 	 */
673 	while ((txs = STAILQ_FIRST(&sc->sc_txdirtyq)) != NULL) {
674 		STAILQ_REMOVE_HEAD(&sc->sc_txdirtyq, txs_q);
675 		if (txs->txs_ndescs != 0) {
676 			bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
677 			    BUS_DMASYNC_POSTWRITE);
678 			bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
679 			if (txs->txs_mbuf != NULL) {
680 				m_freem(txs->txs_mbuf);
681 				txs->txs_mbuf = NULL;
682 			}
683 		}
684 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
685 	}
686 
687 	if (disable)
688 		gem_rxdrain(sc);
689 
690 	/*
691 	 * Mark the interface down and cancel the watchdog timer.
692 	 */
693 	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
694 	sc->sc_flags &= ~GEM_LINK;
695 	sc->sc_wdog_timer = 0;
696 }
697 
698 static int
699 gem_reset_rx(struct gem_softc *sc)
700 {
701 
702 	/*
703 	 * Resetting while DMA is in progress can cause a bus hang, so we
704 	 * disable DMA first.
705 	 */
706 	gem_disable_rx(sc);
707 	GEM_BANK1_WRITE_4(sc, GEM_RX_CONFIG, 0);
708 	GEM_BANK1_BARRIER(sc, GEM_RX_CONFIG, 4,
709 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
710 	if (!GEM_BANK1_BITWAIT(sc, GEM_RX_CONFIG, GEM_RX_CONFIG_RXDMA_EN, 0))
711 		device_printf(sc->sc_dev, "cannot disable RX DMA\n");
712 
713 	/* Finally, reset the ERX. */
714 	GEM_BANK2_WRITE_4(sc, GEM_RESET, GEM_RESET_RX);
715 	GEM_BANK2_BARRIER(sc, GEM_RESET, 4,
716 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
717 	if (!GEM_BANK2_BITWAIT(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX,
718 	    0)) {
719 		device_printf(sc->sc_dev, "cannot reset receiver\n");
720 		return (1);
721 	}
722 	return (0);
723 }
724 
725 /*
726  * Reset the receiver DMA engine.
727  *
728  * Intended to be used in case of GEM_INTR_RX_TAG_ERR, GEM_MAC_RX_OVERFLOW
729  * etc in order to reset the receiver DMA engine only and not do a full
730  * reset which amongst others also downs the link and clears the FIFOs.
731  */
732 static void
733 gem_reset_rxdma(struct gem_softc *sc)
734 {
735 	int i;
736 
737 	if (gem_reset_rx(sc) != 0)
738 		return (gem_init_locked(sc));
739 	for (i = 0; i < GEM_NRXDESC; i++)
740 		if (sc->sc_rxsoft[i].rxs_mbuf != NULL)
741 			GEM_UPDATE_RXDESC(sc, i);
742 	sc->sc_rxptr = 0;
743 	GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
744 
745 	/* NOTE: we use only 32-bit DMA addresses here. */
746 	GEM_BANK1_WRITE_4(sc, GEM_RX_RING_PTR_HI, 0);
747 	GEM_BANK1_WRITE_4(sc, GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
748 	GEM_BANK1_WRITE_4(sc, GEM_RX_KICK, GEM_NRXDESC - 4);
749 	GEM_BANK1_WRITE_4(sc, GEM_RX_CONFIG,
750 	    gem_ringsize(GEM_NRXDESC /* XXX */) |
751 	    ((ETHER_HDR_LEN + sizeof(struct ip)) <<
752 	    GEM_RX_CONFIG_CXM_START_SHFT) |
753 	    (GEM_THRSH_1024 << GEM_RX_CONFIG_FIFO_THRS_SHIFT) |
754 	    (ETHER_ALIGN << GEM_RX_CONFIG_FBOFF_SHFT));
755 	/* Adjust for the SBus clock probably isn't worth the fuzz. */
756 	GEM_BANK1_WRITE_4(sc, GEM_RX_BLANKING,
757 	    ((6 * (sc->sc_flags & GEM_PCI66) != 0 ? 2 : 1) <<
758 	    GEM_RX_BLANKING_TIME_SHIFT) | 6);
759 	GEM_BANK1_WRITE_4(sc, GEM_RX_PAUSE_THRESH,
760 	    (3 * sc->sc_rxfifosize / 256) |
761 	    ((sc->sc_rxfifosize / 256) << 12));
762 	GEM_BANK1_WRITE_4(sc, GEM_RX_CONFIG,
763 	    GEM_BANK1_READ_4(sc, GEM_RX_CONFIG) | GEM_RX_CONFIG_RXDMA_EN);
764 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_MASK,
765 	    GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT);
766 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG,
767 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG) | GEM_MAC_RX_ENABLE);
768 }
769 
770 static int
771 gem_reset_tx(struct gem_softc *sc)
772 {
773 
774 	/*
775 	 * Resetting while DMA is in progress can cause a bus hang, so we
776 	 * disable DMA first.
777 	 */
778 	gem_disable_tx(sc);
779 	GEM_BANK1_WRITE_4(sc, GEM_TX_CONFIG, 0);
780 	GEM_BANK1_BARRIER(sc, GEM_TX_CONFIG, 4,
781 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
782 	if (!GEM_BANK1_BITWAIT(sc, GEM_TX_CONFIG, GEM_TX_CONFIG_TXDMA_EN, 0))
783 		device_printf(sc->sc_dev, "cannot disable TX DMA\n");
784 
785 	/* Finally, reset the ETX. */
786 	GEM_BANK2_WRITE_4(sc, GEM_RESET, GEM_RESET_TX);
787 	GEM_BANK2_BARRIER(sc, GEM_RESET, 4,
788 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
789 	if (!GEM_BANK2_BITWAIT(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX,
790 	    0)) {
791 		device_printf(sc->sc_dev, "cannot reset transmitter\n");
792 		return (1);
793 	}
794 	return (0);
795 }
796 
797 static int
798 gem_disable_rx(struct gem_softc *sc)
799 {
800 
801 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG,
802 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG) & ~GEM_MAC_RX_ENABLE);
803 	GEM_BANK1_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
804 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
805 	return (GEM_BANK1_BITWAIT(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE,
806 	    0));
807 }
808 
809 static int
810 gem_disable_tx(struct gem_softc *sc)
811 {
812 
813 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG,
814 	    GEM_BANK1_READ_4(sc, GEM_MAC_TX_CONFIG) & ~GEM_MAC_TX_ENABLE);
815 	GEM_BANK1_BARRIER(sc, GEM_MAC_TX_CONFIG, 4,
816 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
817 	return (GEM_BANK1_BITWAIT(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE,
818 	    0));
819 }
820 
821 static int
822 gem_meminit(struct gem_softc *sc)
823 {
824 	struct gem_rxsoft *rxs;
825 	int error, i;
826 
827 	GEM_LOCK_ASSERT(sc, MA_OWNED);
828 
829 	/*
830 	 * Initialize the transmit descriptor ring.
831 	 */
832 	for (i = 0; i < GEM_NTXDESC; i++) {
833 		sc->sc_txdescs[i].gd_flags = 0;
834 		sc->sc_txdescs[i].gd_addr = 0;
835 	}
836 	sc->sc_txfree = GEM_MAXTXFREE;
837 	sc->sc_txnext = 0;
838 	sc->sc_txwin = 0;
839 
840 	/*
841 	 * Initialize the receive descriptor and receive job
842 	 * descriptor rings.
843 	 */
844 	for (i = 0; i < GEM_NRXDESC; i++) {
845 		rxs = &sc->sc_rxsoft[i];
846 		if (rxs->rxs_mbuf == NULL) {
847 			if ((error = gem_add_rxbuf(sc, i)) != 0) {
848 				device_printf(sc->sc_dev,
849 				    "unable to allocate or map RX buffer %d, "
850 				    "error = %d\n", i, error);
851 				/*
852 				 * XXX we should attempt to run with fewer
853 				 * receive buffers instead of just failing.
854 				 */
855 				gem_rxdrain(sc);
856 				return (1);
857 			}
858 		} else
859 			GEM_INIT_RXDESC(sc, i);
860 	}
861 	sc->sc_rxptr = 0;
862 
863 	GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
864 
865 	return (0);
866 }
867 
868 static u_int
869 gem_ringsize(u_int sz)
870 {
871 
872 	switch (sz) {
873 	case 32:
874 		return (GEM_RING_SZ_32);
875 	case 64:
876 		return (GEM_RING_SZ_64);
877 	case 128:
878 		return (GEM_RING_SZ_128);
879 	case 256:
880 		return (GEM_RING_SZ_256);
881 	case 512:
882 		return (GEM_RING_SZ_512);
883 	case 1024:
884 		return (GEM_RING_SZ_1024);
885 	case 2048:
886 		return (GEM_RING_SZ_2048);
887 	case 4096:
888 		return (GEM_RING_SZ_4096);
889 	case 8192:
890 		return (GEM_RING_SZ_8192);
891 	default:
892 		printf("%s: invalid ring size %d\n", __func__, sz);
893 		return (GEM_RING_SZ_32);
894 	}
895 }
896 
897 static void
898 gem_init(void *xsc)
899 {
900 	struct gem_softc *sc = xsc;
901 
902 	GEM_LOCK(sc);
903 	gem_init_locked(sc);
904 	GEM_UNLOCK(sc);
905 }
906 
907 /*
908  * Initialization of interface; set up initialization block
909  * and transmit/receive descriptor rings.
910  */
911 static void
912 gem_init_locked(struct gem_softc *sc)
913 {
914 	struct ifnet *ifp = sc->sc_ifp;
915 	uint32_t v;
916 
917 	GEM_LOCK_ASSERT(sc, MA_OWNED);
918 
919 #ifdef GEM_DEBUG
920 	CTR2(KTR_GEM, "%s: %s: calling stop", device_get_name(sc->sc_dev),
921 	    __func__);
922 #endif
923 	/*
924 	 * Initialization sequence.  The numbered steps below correspond
925 	 * to the sequence outlined in section 6.3.5.1 in the Ethernet
926 	 * Channel Engine manual (part of the PCIO manual).
927 	 * See also the STP2002-STQ document from Sun Microsystems.
928 	 */
929 
930 	/* step 1 & 2.  Reset the Ethernet Channel. */
931 	gem_stop(ifp, 0);
932 	gem_reset(sc);
933 #ifdef GEM_DEBUG
934 	CTR2(KTR_GEM, "%s: %s: restarting", device_get_name(sc->sc_dev),
935 	    __func__);
936 #endif
937 
938 	if ((sc->sc_flags & GEM_SERDES) == 0)
939 		/* Re-initialize the MIF. */
940 		gem_mifinit(sc);
941 
942 	/* step 3.  Setup data structures in host memory. */
943 	if (gem_meminit(sc) != 0)
944 		return;
945 
946 	/* step 4.  TX MAC registers & counters */
947 	gem_init_regs(sc);
948 
949 	/* step 5.  RX MAC registers & counters */
950 	gem_setladrf(sc);
951 
952 	/* step 6 & 7.  Program Descriptor Ring Base Addresses. */
953 	/* NOTE: we use only 32-bit DMA addresses here. */
954 	GEM_BANK1_WRITE_4(sc, GEM_TX_RING_PTR_HI, 0);
955 	GEM_BANK1_WRITE_4(sc, GEM_TX_RING_PTR_LO, GEM_CDTXADDR(sc, 0));
956 
957 	GEM_BANK1_WRITE_4(sc, GEM_RX_RING_PTR_HI, 0);
958 	GEM_BANK1_WRITE_4(sc, GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
959 #ifdef GEM_DEBUG
960 	CTR3(KTR_GEM, "loading RX ring %lx, TX ring %lx, cddma %lx",
961 	    GEM_CDRXADDR(sc, 0), GEM_CDTXADDR(sc, 0), sc->sc_cddma);
962 #endif
963 
964 	/* step 8.  Global Configuration & Interrupt Mask */
965 
966 	/*
967 	 * Set the internal arbitration to "infinite" bursts of the
968 	 * maximum length of 31 * 64 bytes so DMA transfers aren't
969 	 * split up in cache line size chunks.  This greatly improves
970 	 * RX performance.
971 	 * Enable silicon bug workarounds for the Apple variants.
972 	 */
973 	GEM_BANK1_WRITE_4(sc, GEM_CONFIG,
974 	    GEM_CONFIG_TXDMA_LIMIT | GEM_CONFIG_RXDMA_LIMIT |
975 	    ((sc->sc_flags & GEM_PCI) != 0 ? GEM_CONFIG_BURST_INF :
976 	    GEM_CONFIG_BURST_64) | (GEM_IS_APPLE(sc) ?
977 	    GEM_CONFIG_RONPAULBIT | GEM_CONFIG_BUG2FIX : 0));
978 
979 	GEM_BANK1_WRITE_4(sc, GEM_INTMASK,
980 	    ~(GEM_INTR_TX_INTME | GEM_INTR_TX_EMPTY | GEM_INTR_RX_DONE |
981 	    GEM_INTR_RX_NOBUF | GEM_INTR_RX_TAG_ERR | GEM_INTR_PERR |
982 	    GEM_INTR_BERR
983 #ifdef GEM_DEBUG
984 	    | GEM_INTR_PCS | GEM_INTR_MIF
985 #endif
986 	    ));
987 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_MASK,
988 	    GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT);
989 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_MASK,
990 	    GEM_MAC_TX_XMIT_DONE | GEM_MAC_TX_DEFER_EXP |
991 	    GEM_MAC_TX_PEAK_EXP);
992 #ifdef GEM_DEBUG
993 	GEM_BANK1_WRITE_4(sc, GEM_MAC_CONTROL_MASK,
994 	    ~(GEM_MAC_PAUSED | GEM_MAC_PAUSE | GEM_MAC_RESUME));
995 #else
996 	GEM_BANK1_WRITE_4(sc, GEM_MAC_CONTROL_MASK,
997 	    GEM_MAC_PAUSED | GEM_MAC_PAUSE | GEM_MAC_RESUME);
998 #endif
999 
1000 	/* step 9.  ETX Configuration: use mostly default values. */
1001 
1002 	/* Enable DMA. */
1003 	v = gem_ringsize(GEM_NTXDESC);
1004 	/* Set TX FIFO threshold and enable DMA. */
1005 	v |= ((sc->sc_variant == GEM_SUN_ERI ? 0x100 : 0x4ff) << 10) &
1006 	    GEM_TX_CONFIG_TXFIFO_TH;
1007 	GEM_BANK1_WRITE_4(sc, GEM_TX_CONFIG, v | GEM_TX_CONFIG_TXDMA_EN);
1008 
1009 	/* step 10.  ERX Configuration */
1010 
1011 	/* Encode Receive Descriptor ring size. */
1012 	v = gem_ringsize(GEM_NRXDESC /* XXX */);
1013 	/* RX TCP/UDP checksum offset */
1014 	v |= ((ETHER_HDR_LEN + sizeof(struct ip)) <<
1015 	    GEM_RX_CONFIG_CXM_START_SHFT);
1016 	/* Set RX FIFO threshold, set first byte offset and enable DMA. */
1017 	GEM_BANK1_WRITE_4(sc, GEM_RX_CONFIG,
1018 	    v | (GEM_THRSH_1024 << GEM_RX_CONFIG_FIFO_THRS_SHIFT) |
1019 	    (ETHER_ALIGN << GEM_RX_CONFIG_FBOFF_SHFT) |
1020 	    GEM_RX_CONFIG_RXDMA_EN);
1021 
1022 	/* Adjust for the SBus clock probably isn't worth the fuzz. */
1023 	GEM_BANK1_WRITE_4(sc, GEM_RX_BLANKING,
1024 	    ((6 * (sc->sc_flags & GEM_PCI66) != 0 ? 2 : 1) <<
1025 	    GEM_RX_BLANKING_TIME_SHIFT) | 6);
1026 
1027 	/*
1028 	 * The following value is for an OFF Threshold of about 3/4 full
1029 	 * and an ON Threshold of 1/4 full.
1030 	 */
1031 	GEM_BANK1_WRITE_4(sc, GEM_RX_PAUSE_THRESH,
1032 	    (3 * sc->sc_rxfifosize / 256) |
1033 	    ((sc->sc_rxfifosize / 256) << 12));
1034 
1035 	/* step 11.  Configure Media. */
1036 
1037 	/* step 12.  RX_MAC Configuration Register */
1038 	v = GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG);
1039 	v |= GEM_MAC_RX_ENABLE | GEM_MAC_RX_STRIP_CRC;
1040 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, 0);
1041 	GEM_BANK1_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
1042 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1043 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0))
1044 		device_printf(sc->sc_dev, "cannot configure RX MAC\n");
1045 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, v);
1046 
1047 	/* step 13.  TX_MAC Configuration Register */
1048 	v = GEM_BANK1_READ_4(sc, GEM_MAC_TX_CONFIG);
1049 	v |= GEM_MAC_TX_ENABLE;
1050 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG, 0);
1051 	GEM_BANK1_BARRIER(sc, GEM_MAC_TX_CONFIG, 4,
1052 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1053 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0))
1054 		device_printf(sc->sc_dev, "cannot configure TX MAC\n");
1055 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG, v);
1056 
1057 	/* step 14.  Issue Transmit Pending command. */
1058 
1059 	/* step 15.  Give the reciever a swift kick. */
1060 	GEM_BANK1_WRITE_4(sc, GEM_RX_KICK, GEM_NRXDESC - 4);
1061 
1062 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
1063 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1064 
1065 	mii_mediachg(sc->sc_mii);
1066 
1067 	/* Start the one second timer. */
1068 	sc->sc_wdog_timer = 0;
1069 	callout_reset(&sc->sc_tick_ch, hz, gem_tick, sc);
1070 }
1071 
1072 static int
1073 gem_load_txmbuf(struct gem_softc *sc, struct mbuf **m_head)
1074 {
1075 	bus_dma_segment_t txsegs[GEM_NTXSEGS];
1076 	struct gem_txsoft *txs;
1077 	struct ip *ip;
1078 	struct mbuf *m;
1079 	uint64_t cflags, flags;
1080 	int error, nexttx, nsegs, offset, seg;
1081 
1082 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1083 
1084 	/* Get a work queue entry. */
1085 	if ((txs = STAILQ_FIRST(&sc->sc_txfreeq)) == NULL) {
1086 		/* Ran out of descriptors. */
1087 		return (ENOBUFS);
1088 	}
1089 
1090 	cflags = 0;
1091 	if (((*m_head)->m_pkthdr.csum_flags & sc->sc_csum_features) != 0) {
1092 		if (M_WRITABLE(*m_head) == 0) {
1093 			m = m_dup(*m_head, M_DONTWAIT);
1094 			m_freem(*m_head);
1095 			*m_head = m;
1096 			if (m == NULL)
1097 				return (ENOBUFS);
1098 		}
1099 		offset = sizeof(struct ether_header);
1100 		m = m_pullup(*m_head, offset + sizeof(struct ip));
1101 		if (m == NULL) {
1102 			*m_head = NULL;
1103 			return (ENOBUFS);
1104 		}
1105 		ip = (struct ip *)(mtod(m, caddr_t) + offset);
1106 		offset += (ip->ip_hl << 2);
1107 		cflags = offset << GEM_TD_CXSUM_STARTSHFT |
1108 		    ((offset + m->m_pkthdr.csum_data) <<
1109 		    GEM_TD_CXSUM_STUFFSHFT) | GEM_TD_CXSUM_ENABLE;
1110 		*m_head = m;
1111 	}
1112 
1113 	error = bus_dmamap_load_mbuf_sg(sc->sc_tdmatag, txs->txs_dmamap,
1114 	    *m_head, txsegs, &nsegs, BUS_DMA_NOWAIT);
1115 	if (error == EFBIG) {
1116 		m = m_collapse(*m_head, M_DONTWAIT, GEM_NTXSEGS);
1117 		if (m == NULL) {
1118 			m_freem(*m_head);
1119 			*m_head = NULL;
1120 			return (ENOBUFS);
1121 		}
1122 		*m_head = m;
1123 		error = bus_dmamap_load_mbuf_sg(sc->sc_tdmatag,
1124 		    txs->txs_dmamap, *m_head, txsegs, &nsegs,
1125 		    BUS_DMA_NOWAIT);
1126 		if (error != 0) {
1127 			m_freem(*m_head);
1128 			*m_head = NULL;
1129 			return (error);
1130 		}
1131 	} else if (error != 0)
1132 		return (error);
1133 	/* If nsegs is wrong then the stack is corrupt. */
1134 	KASSERT(nsegs <= GEM_NTXSEGS,
1135 	    ("%s: too many DMA segments (%d)", __func__, nsegs));
1136 	if (nsegs == 0) {
1137 		m_freem(*m_head);
1138 		*m_head = NULL;
1139 		return (EIO);
1140 	}
1141 
1142 	/*
1143 	 * Ensure we have enough descriptors free to describe
1144 	 * the packet.  Note, we always reserve one descriptor
1145 	 * at the end of the ring as a termination point, in
1146 	 * order to prevent wrap-around.
1147 	 */
1148 	if (nsegs > sc->sc_txfree - 1) {
1149 		txs->txs_ndescs = 0;
1150 		bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
1151 		return (ENOBUFS);
1152 	}
1153 
1154 	txs->txs_ndescs = nsegs;
1155 	txs->txs_firstdesc = sc->sc_txnext;
1156 	nexttx = txs->txs_firstdesc;
1157 	for (seg = 0; seg < nsegs; seg++, nexttx = GEM_NEXTTX(nexttx)) {
1158 #ifdef GEM_DEBUG
1159 		CTR6(KTR_GEM,
1160 		    "%s: mapping seg %d (txd %d), len %lx, addr %#lx (%#lx)",
1161 		    __func__, seg, nexttx, txsegs[seg].ds_len,
1162 		    txsegs[seg].ds_addr,
1163 		    GEM_DMA_WRITE(sc, txsegs[seg].ds_addr));
1164 #endif
1165 		sc->sc_txdescs[nexttx].gd_addr =
1166 		    GEM_DMA_WRITE(sc, txsegs[seg].ds_addr);
1167 		KASSERT(txsegs[seg].ds_len < GEM_TD_BUFSIZE,
1168 		    ("%s: segment size too large!", __func__));
1169 		flags = txsegs[seg].ds_len & GEM_TD_BUFSIZE;
1170 		sc->sc_txdescs[nexttx].gd_flags =
1171 		    GEM_DMA_WRITE(sc, flags | cflags);
1172 		txs->txs_lastdesc = nexttx;
1173 	}
1174 
1175 	/* Set EOP on the last descriptor. */
1176 #ifdef GEM_DEBUG
1177 	CTR3(KTR_GEM, "%s: end of packet at segment %d, TX %d",
1178 	    __func__, seg, nexttx);
1179 #endif
1180 	sc->sc_txdescs[txs->txs_lastdesc].gd_flags |=
1181 	    GEM_DMA_WRITE(sc, GEM_TD_END_OF_PACKET);
1182 
1183 	/* Lastly set SOP on the first descriptor. */
1184 #ifdef GEM_DEBUG
1185 	CTR3(KTR_GEM, "%s: start of packet at segment %d, TX %d",
1186 	    __func__, seg, nexttx);
1187 #endif
1188 	if (++sc->sc_txwin > GEM_NTXSEGS * 2 / 3) {
1189 		sc->sc_txwin = 0;
1190 		sc->sc_txdescs[txs->txs_firstdesc].gd_flags |=
1191 		    GEM_DMA_WRITE(sc, GEM_TD_INTERRUPT_ME |
1192 		    GEM_TD_START_OF_PACKET);
1193 	} else
1194 		sc->sc_txdescs[txs->txs_firstdesc].gd_flags |=
1195 		    GEM_DMA_WRITE(sc, GEM_TD_START_OF_PACKET);
1196 
1197 	/* Sync the DMA map. */
1198 	bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
1199 	    BUS_DMASYNC_PREWRITE);
1200 
1201 #ifdef GEM_DEBUG
1202 	CTR4(KTR_GEM, "%s: setting firstdesc=%d, lastdesc=%d, ndescs=%d",
1203 	    __func__, txs->txs_firstdesc, txs->txs_lastdesc,
1204 	    txs->txs_ndescs);
1205 #endif
1206 	STAILQ_REMOVE_HEAD(&sc->sc_txfreeq, txs_q);
1207 	STAILQ_INSERT_TAIL(&sc->sc_txdirtyq, txs, txs_q);
1208 	txs->txs_mbuf = *m_head;
1209 
1210 	sc->sc_txnext = GEM_NEXTTX(txs->txs_lastdesc);
1211 	sc->sc_txfree -= txs->txs_ndescs;
1212 
1213 	return (0);
1214 }
1215 
1216 static void
1217 gem_init_regs(struct gem_softc *sc)
1218 {
1219 	const u_char *laddr = IF_LLADDR(sc->sc_ifp);
1220 
1221 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1222 
1223 	/* These registers are not cleared on reset. */
1224 	if ((sc->sc_flags & GEM_INITED) == 0) {
1225 		/* magic values */
1226 		GEM_BANK1_WRITE_4(sc, GEM_MAC_IPG0, 0);
1227 		GEM_BANK1_WRITE_4(sc, GEM_MAC_IPG1, 8);
1228 		GEM_BANK1_WRITE_4(sc, GEM_MAC_IPG2, 4);
1229 
1230 		/* min frame length */
1231 		GEM_BANK1_WRITE_4(sc, GEM_MAC_MAC_MIN_FRAME, ETHER_MIN_LEN);
1232 		/* max frame length and max burst size */
1233 		GEM_BANK1_WRITE_4(sc, GEM_MAC_MAC_MAX_FRAME,
1234 		    (ETHER_MAX_LEN + ETHER_VLAN_ENCAP_LEN) | (0x2000 << 16));
1235 
1236 		/* more magic values */
1237 		GEM_BANK1_WRITE_4(sc, GEM_MAC_PREAMBLE_LEN, 0x7);
1238 		GEM_BANK1_WRITE_4(sc, GEM_MAC_JAM_SIZE, 0x4);
1239 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ATTEMPT_LIMIT, 0x10);
1240 		GEM_BANK1_WRITE_4(sc, GEM_MAC_CONTROL_TYPE, 0x8088);
1241 
1242 		/* random number seed */
1243 		GEM_BANK1_WRITE_4(sc, GEM_MAC_RANDOM_SEED,
1244 		    ((laddr[5] << 8) | laddr[4]) & 0x3ff);
1245 
1246 		/* secondary MAC address: 0:0:0:0:0:0 */
1247 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR3, 0);
1248 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR4, 0);
1249 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR5, 0);
1250 
1251 		/* MAC control address: 01:80:c2:00:00:01 */
1252 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR6, 0x0001);
1253 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR7, 0xc200);
1254 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR8, 0x0180);
1255 
1256 		/* MAC filter address: 0:0:0:0:0:0 */
1257 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR_FILTER0, 0);
1258 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR_FILTER1, 0);
1259 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR_FILTER2, 0);
1260 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADR_FLT_MASK1_2, 0);
1261 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADR_FLT_MASK0, 0);
1262 
1263 		sc->sc_flags |= GEM_INITED;
1264 	}
1265 
1266 	/* Counters need to be zeroed. */
1267 	GEM_BANK1_WRITE_4(sc, GEM_MAC_NORM_COLL_CNT, 0);
1268 	GEM_BANK1_WRITE_4(sc, GEM_MAC_FIRST_COLL_CNT, 0);
1269 	GEM_BANK1_WRITE_4(sc, GEM_MAC_EXCESS_COLL_CNT, 0);
1270 	GEM_BANK1_WRITE_4(sc, GEM_MAC_LATE_COLL_CNT, 0);
1271 	GEM_BANK1_WRITE_4(sc, GEM_MAC_DEFER_TMR_CNT, 0);
1272 	GEM_BANK1_WRITE_4(sc, GEM_MAC_PEAK_ATTEMPTS, 0);
1273 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_FRAME_COUNT, 0);
1274 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_LEN_ERR_CNT, 0);
1275 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_ALIGN_ERR, 0);
1276 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CRC_ERR_CNT, 0);
1277 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CODE_VIOL, 0);
1278 
1279 	/* Set XOFF PAUSE time. */
1280 	GEM_BANK1_WRITE_4(sc, GEM_MAC_SEND_PAUSE_CMD, 0x1BF0);
1281 
1282 	/* Set the station address. */
1283 	GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR0, (laddr[4] << 8) | laddr[5]);
1284 	GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR1, (laddr[2] << 8) | laddr[3]);
1285 	GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR2, (laddr[0] << 8) | laddr[1]);
1286 
1287 	/* Enable MII outputs. */
1288 	GEM_BANK1_WRITE_4(sc, GEM_MAC_XIF_CONFIG, GEM_MAC_XIF_TX_MII_ENA);
1289 }
1290 
1291 static void
1292 gem_start(struct ifnet *ifp)
1293 {
1294 	struct gem_softc *sc = ifp->if_softc;
1295 
1296 	GEM_LOCK(sc);
1297 	gem_start_locked(ifp);
1298 	GEM_UNLOCK(sc);
1299 }
1300 
1301 static inline void
1302 gem_txkick(struct gem_softc *sc)
1303 {
1304 
1305 	/*
1306 	 * Update the TX kick register.  This register has to point to the
1307 	 * descriptor after the last valid one and for optimum performance
1308 	 * should be incremented in multiples of 4 (the DMA engine fetches/
1309 	 * updates descriptors in batches of 4).
1310 	 */
1311 #ifdef GEM_DEBUG
1312 	CTR3(KTR_GEM, "%s: %s: kicking TX %d",
1313 	    device_get_name(sc->sc_dev), __func__, sc->sc_txnext);
1314 #endif
1315 	GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
1316 	GEM_BANK1_WRITE_4(sc, GEM_TX_KICK, sc->sc_txnext);
1317 }
1318 
1319 static void
1320 gem_start_locked(struct ifnet *ifp)
1321 {
1322 	struct gem_softc *sc = ifp->if_softc;
1323 	struct mbuf *m;
1324 	int kicked, ntx;
1325 
1326 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1327 
1328 	if ((ifp->if_drv_flags & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
1329 	    IFF_DRV_RUNNING || (sc->sc_flags & GEM_LINK) == 0)
1330 		return;
1331 
1332 #ifdef GEM_DEBUG
1333 	CTR4(KTR_GEM, "%s: %s: txfree %d, txnext %d",
1334 	    device_get_name(sc->sc_dev), __func__, sc->sc_txfree,
1335 	    sc->sc_txnext);
1336 #endif
1337 	ntx = 0;
1338 	kicked = 0;
1339 	for (; !IFQ_DRV_IS_EMPTY(&ifp->if_snd) && sc->sc_txfree > 1;) {
1340 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
1341 		if (m == NULL)
1342 			break;
1343 		if (gem_load_txmbuf(sc, &m) != 0) {
1344 			if (m == NULL)
1345 				break;
1346 			ifp->if_drv_flags |= IFF_DRV_OACTIVE;
1347 			IFQ_DRV_PREPEND(&ifp->if_snd, m);
1348 			break;
1349 		}
1350 		if ((sc->sc_txnext % 4) == 0) {
1351 			gem_txkick(sc);
1352 			kicked = 1;
1353 		} else
1354 			kicked = 0;
1355 		ntx++;
1356 		BPF_MTAP(ifp, m);
1357 	}
1358 
1359 	if (ntx > 0) {
1360 		if (kicked == 0)
1361 			gem_txkick(sc);
1362 #ifdef GEM_DEBUG
1363 		CTR2(KTR_GEM, "%s: packets enqueued, OWN on %d",
1364 		    device_get_name(sc->sc_dev), sc->sc_txnext);
1365 #endif
1366 
1367 		/* Set a watchdog timer in case the chip flakes out. */
1368 		sc->sc_wdog_timer = 5;
1369 #ifdef GEM_DEBUG
1370 		CTR3(KTR_GEM, "%s: %s: watchdog %d",
1371 		    device_get_name(sc->sc_dev), __func__,
1372 		    sc->sc_wdog_timer);
1373 #endif
1374 	}
1375 }
1376 
1377 static void
1378 gem_tint(struct gem_softc *sc)
1379 {
1380 	struct ifnet *ifp = sc->sc_ifp;
1381 	struct gem_txsoft *txs;
1382 	int progress;
1383 	uint32_t txlast;
1384 #ifdef GEM_DEBUG
1385 	int i;
1386 
1387 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1388 
1389 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
1390 #endif
1391 
1392 	/*
1393 	 * Go through our TX list and free mbufs for those
1394 	 * frames that have been transmitted.
1395 	 */
1396 	progress = 0;
1397 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD);
1398 	while ((txs = STAILQ_FIRST(&sc->sc_txdirtyq)) != NULL) {
1399 #ifdef GEM_DEBUG
1400 		if ((ifp->if_flags & IFF_DEBUG) != 0) {
1401 			printf("    txsoft %p transmit chain:\n", txs);
1402 			for (i = txs->txs_firstdesc;; i = GEM_NEXTTX(i)) {
1403 				printf("descriptor %d: ", i);
1404 				printf("gd_flags: 0x%016llx\t",
1405 				    (long long)GEM_DMA_READ(sc,
1406 				    sc->sc_txdescs[i].gd_flags));
1407 				printf("gd_addr: 0x%016llx\n",
1408 				    (long long)GEM_DMA_READ(sc,
1409 				    sc->sc_txdescs[i].gd_addr));
1410 				if (i == txs->txs_lastdesc)
1411 					break;
1412 			}
1413 		}
1414 #endif
1415 
1416 		/*
1417 		 * In theory, we could harvest some descriptors before
1418 		 * the ring is empty, but that's a bit complicated.
1419 		 *
1420 		 * GEM_TX_COMPLETION points to the last descriptor
1421 		 * processed + 1.
1422 		 */
1423 		txlast = GEM_BANK1_READ_4(sc, GEM_TX_COMPLETION);
1424 #ifdef GEM_DEBUG
1425 		CTR4(KTR_GEM, "%s: txs->txs_firstdesc = %d, "
1426 		    "txs->txs_lastdesc = %d, txlast = %d",
1427 		    __func__, txs->txs_firstdesc, txs->txs_lastdesc, txlast);
1428 #endif
1429 		if (txs->txs_firstdesc <= txs->txs_lastdesc) {
1430 			if ((txlast >= txs->txs_firstdesc) &&
1431 			    (txlast <= txs->txs_lastdesc))
1432 				break;
1433 		} else {
1434 			/* Ick -- this command wraps. */
1435 			if ((txlast >= txs->txs_firstdesc) ||
1436 			    (txlast <= txs->txs_lastdesc))
1437 				break;
1438 		}
1439 
1440 #ifdef GEM_DEBUG
1441 		CTR1(KTR_GEM, "%s: releasing a descriptor", __func__);
1442 #endif
1443 		STAILQ_REMOVE_HEAD(&sc->sc_txdirtyq, txs_q);
1444 
1445 		sc->sc_txfree += txs->txs_ndescs;
1446 
1447 		bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
1448 		    BUS_DMASYNC_POSTWRITE);
1449 		bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
1450 		if (txs->txs_mbuf != NULL) {
1451 			m_freem(txs->txs_mbuf);
1452 			txs->txs_mbuf = NULL;
1453 		}
1454 
1455 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
1456 
1457 		ifp->if_opackets++;
1458 		progress = 1;
1459 	}
1460 
1461 #ifdef GEM_DEBUG
1462 	CTR4(KTR_GEM, "%s: GEM_TX_STATE_MACHINE %x GEM_TX_DATA_PTR %llx "
1463 	    "GEM_TX_COMPLETION %x",
1464 	    __func__, GEM_BANK1_READ_4(sc, GEM_TX_STATE_MACHINE),
1465 	    ((long long)GEM_BANK1_READ_4(sc, GEM_TX_DATA_PTR_HI) << 32) |
1466 	    GEM_BANK1_READ_4(sc, GEM_TX_DATA_PTR_LO),
1467 	    GEM_BANK1_READ_4(sc, GEM_TX_COMPLETION));
1468 #endif
1469 
1470 	if (progress) {
1471 		if (sc->sc_txfree == GEM_NTXDESC - 1)
1472 			sc->sc_txwin = 0;
1473 
1474 		/*
1475 		 * We freed some descriptors, so reset IFF_DRV_OACTIVE
1476 		 * and restart.
1477 		 */
1478 		ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1479 		if (STAILQ_EMPTY(&sc->sc_txdirtyq))
1480 		    sc->sc_wdog_timer = 0;
1481 		gem_start_locked(ifp);
1482 	}
1483 
1484 #ifdef GEM_DEBUG
1485 	CTR3(KTR_GEM, "%s: %s: watchdog %d",
1486 	    device_get_name(sc->sc_dev), __func__, sc->sc_wdog_timer);
1487 #endif
1488 }
1489 
1490 #ifdef GEM_RINT_TIMEOUT
1491 static void
1492 gem_rint_timeout(void *arg)
1493 {
1494 	struct gem_softc *sc = arg;
1495 
1496 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1497 
1498 	gem_rint(sc);
1499 }
1500 #endif
1501 
1502 static void
1503 gem_rint(struct gem_softc *sc)
1504 {
1505 	struct ifnet *ifp = sc->sc_ifp;
1506 	struct mbuf *m;
1507 	uint64_t rxstat;
1508 	uint32_t rxcomp;
1509 
1510 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1511 
1512 #ifdef GEM_RINT_TIMEOUT
1513 	callout_stop(&sc->sc_rx_ch);
1514 #endif
1515 #ifdef GEM_DEBUG
1516 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
1517 #endif
1518 
1519 	/*
1520 	 * Read the completion register once.  This limits
1521 	 * how long the following loop can execute.
1522 	 */
1523 	rxcomp = GEM_BANK1_READ_4(sc, GEM_RX_COMPLETION);
1524 #ifdef GEM_DEBUG
1525 	CTR3(KTR_GEM, "%s: sc->sc_rxptr %d, complete %d",
1526 	    __func__, sc->sc_rxptr, rxcomp);
1527 #endif
1528 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
1529 	for (; sc->sc_rxptr != rxcomp;) {
1530 		m = sc->sc_rxsoft[sc->sc_rxptr].rxs_mbuf;
1531 		rxstat = GEM_DMA_READ(sc,
1532 		    sc->sc_rxdescs[sc->sc_rxptr].gd_flags);
1533 
1534 		if (rxstat & GEM_RD_OWN) {
1535 #ifdef GEM_RINT_TIMEOUT
1536 			/*
1537 			 * The descriptor is still marked as owned, although
1538 			 * it is supposed to have completed.  This has been
1539 			 * observed on some machines.  Just exiting here
1540 			 * might leave the packet sitting around until another
1541 			 * one arrives to trigger a new interrupt, which is
1542 			 * generally undesirable, so set up a timeout.
1543 			 */
1544 			callout_reset(&sc->sc_rx_ch, GEM_RXOWN_TICKS,
1545 			    gem_rint_timeout, sc);
1546 #endif
1547 			m = NULL;
1548 			goto kickit;
1549 		}
1550 
1551 		if (rxstat & GEM_RD_BAD_CRC) {
1552 			ifp->if_ierrors++;
1553 			device_printf(sc->sc_dev, "receive error: CRC error\n");
1554 			GEM_INIT_RXDESC(sc, sc->sc_rxptr);
1555 			m = NULL;
1556 			goto kickit;
1557 		}
1558 
1559 #ifdef GEM_DEBUG
1560 		if ((ifp->if_flags & IFF_DEBUG) != 0) {
1561 			printf("    rxsoft %p descriptor %d: ",
1562 			    &sc->sc_rxsoft[sc->sc_rxptr], sc->sc_rxptr);
1563 			printf("gd_flags: 0x%016llx\t",
1564 			    (long long)GEM_DMA_READ(sc,
1565 			    sc->sc_rxdescs[sc->sc_rxptr].gd_flags));
1566 			printf("gd_addr: 0x%016llx\n",
1567 			    (long long)GEM_DMA_READ(sc,
1568 			    sc->sc_rxdescs[sc->sc_rxptr].gd_addr));
1569 		}
1570 #endif
1571 
1572 		/*
1573 		 * Allocate a new mbuf cluster.  If that fails, we are
1574 		 * out of memory, and must drop the packet and recycle
1575 		 * the buffer that's already attached to this descriptor.
1576 		 */
1577 		if (gem_add_rxbuf(sc, sc->sc_rxptr) != 0) {
1578 			ifp->if_ierrors++;
1579 			GEM_INIT_RXDESC(sc, sc->sc_rxptr);
1580 			m = NULL;
1581 		}
1582 
1583  kickit:
1584 		/*
1585 		 * Update the RX kick register.  This register has to point
1586 		 * to the descriptor after the last valid one (before the
1587 		 * current batch) and for optimum performance should be
1588 		 * incremented in multiples of 4 (the DMA engine fetches/
1589 		 * updates descriptors in batches of 4).
1590 		 */
1591 		sc->sc_rxptr = GEM_NEXTRX(sc->sc_rxptr);
1592 		if ((sc->sc_rxptr % 4) == 0) {
1593 			GEM_CDSYNC(sc,
1594 			    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
1595 			GEM_BANK1_WRITE_4(sc, GEM_RX_KICK,
1596 			    (sc->sc_rxptr + GEM_NRXDESC - 4) &
1597 			    GEM_NRXDESC_MASK);
1598 		}
1599 
1600 		if (m == NULL) {
1601 			if (rxstat & GEM_RD_OWN)
1602 				break;
1603 			continue;
1604 		}
1605 
1606 		ifp->if_ipackets++;
1607 		m->m_data += ETHER_ALIGN; /* first byte offset */
1608 		m->m_pkthdr.rcvif = ifp;
1609 		m->m_pkthdr.len = m->m_len = GEM_RD_BUFLEN(rxstat);
1610 
1611 		if ((ifp->if_capenable & IFCAP_RXCSUM) != 0)
1612 			gem_rxcksum(m, rxstat);
1613 
1614 		/* Pass it on. */
1615 		GEM_UNLOCK(sc);
1616 		(*ifp->if_input)(ifp, m);
1617 		GEM_LOCK(sc);
1618 	}
1619 
1620 #ifdef GEM_DEBUG
1621 	CTR3(KTR_GEM, "%s: done sc->sc_rxptr %d, complete %d", __func__,
1622 	    sc->sc_rxptr, GEM_BANK1_READ_4(sc, GEM_RX_COMPLETION));
1623 #endif
1624 }
1625 
1626 static int
1627 gem_add_rxbuf(struct gem_softc *sc, int idx)
1628 {
1629 	struct gem_rxsoft *rxs = &sc->sc_rxsoft[idx];
1630 	struct mbuf *m;
1631 	bus_dma_segment_t segs[1];
1632 	int error, nsegs;
1633 
1634 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1635 
1636 	m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
1637 	if (m == NULL)
1638 		return (ENOBUFS);
1639 	m->m_len = m->m_pkthdr.len = m->m_ext.ext_size;
1640 
1641 #ifdef GEM_DEBUG
1642 	/* Bzero the packet to check DMA. */
1643 	memset(m->m_ext.ext_buf, 0, m->m_ext.ext_size);
1644 #endif
1645 
1646 	if (rxs->rxs_mbuf != NULL) {
1647 		bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
1648 		    BUS_DMASYNC_POSTREAD);
1649 		bus_dmamap_unload(sc->sc_rdmatag, rxs->rxs_dmamap);
1650 	}
1651 
1652 	error = bus_dmamap_load_mbuf_sg(sc->sc_rdmatag, rxs->rxs_dmamap,
1653 	    m, segs, &nsegs, BUS_DMA_NOWAIT);
1654 	if (error != 0) {
1655 		device_printf(sc->sc_dev,
1656 		    "cannot load RS DMA map %d, error = %d\n", idx, error);
1657 		m_freem(m);
1658 		return (error);
1659 	}
1660 	/* If nsegs is wrong then the stack is corrupt. */
1661 	KASSERT(nsegs == 1,
1662 	    ("%s: too many DMA segments (%d)", __func__, nsegs));
1663 	rxs->rxs_mbuf = m;
1664 	rxs->rxs_paddr = segs[0].ds_addr;
1665 
1666 	bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
1667 	    BUS_DMASYNC_PREREAD);
1668 
1669 	GEM_INIT_RXDESC(sc, idx);
1670 
1671 	return (0);
1672 }
1673 
1674 static void
1675 gem_eint(struct gem_softc *sc, u_int status)
1676 {
1677 
1678 	sc->sc_ifp->if_ierrors++;
1679 	if ((status & GEM_INTR_RX_TAG_ERR) != 0) {
1680 		gem_reset_rxdma(sc);
1681 		return;
1682 	}
1683 
1684 	device_printf(sc->sc_dev, "%s: status 0x%x", __func__, status);
1685 	if ((status & GEM_INTR_BERR) != 0) {
1686 		if ((sc->sc_flags & GEM_PCI) != 0)
1687 			printf(", PCI bus error 0x%x\n",
1688 			    GEM_BANK1_READ_4(sc, GEM_PCI_ERROR_STATUS));
1689 		else
1690 			printf(", SBus error 0x%x\n",
1691 			    GEM_BANK1_READ_4(sc, GEM_SBUS_STATUS));
1692 	}
1693 }
1694 
1695 void
1696 gem_intr(void *v)
1697 {
1698 	struct gem_softc *sc = v;
1699 	uint32_t status, status2;
1700 
1701 	GEM_LOCK(sc);
1702 	status = GEM_BANK1_READ_4(sc, GEM_STATUS);
1703 
1704 #ifdef GEM_DEBUG
1705 	CTR4(KTR_GEM, "%s: %s: cplt %x, status %x",
1706 	    device_get_name(sc->sc_dev), __func__,
1707 	    (status >> GEM_STATUS_TX_COMPLETION_SHFT), (u_int)status);
1708 
1709 	/*
1710 	 * PCS interrupts must be cleared, otherwise no traffic is passed!
1711 	 */
1712 	if ((status & GEM_INTR_PCS) != 0) {
1713 		status2 =
1714 		    GEM_BANK1_READ_4(sc, GEM_MII_INTERRUP_STATUS) |
1715 		    GEM_BANK1_READ_4(sc, GEM_MII_INTERRUP_STATUS);
1716 		if ((status2 & GEM_MII_INTERRUP_LINK) != 0)
1717 			device_printf(sc->sc_dev,
1718 			    "%s: PCS link status changed\n", __func__);
1719 	}
1720 	if ((status & GEM_MAC_CONTROL_STATUS) != 0) {
1721 		status2 = GEM_BANK1_READ_4(sc, GEM_MAC_CONTROL_STATUS);
1722 		if ((status2 & GEM_MAC_PAUSED) != 0)
1723 			device_printf(sc->sc_dev,
1724 			    "%s: PAUSE received (PAUSE time %d slots)\n",
1725 			    __func__, GEM_MAC_PAUSE_TIME(status2));
1726 		if ((status2 & GEM_MAC_PAUSE) != 0)
1727 			device_printf(sc->sc_dev,
1728 			    "%s: transited to PAUSE state\n", __func__);
1729 		if ((status2 & GEM_MAC_RESUME) != 0)
1730 			device_printf(sc->sc_dev,
1731 			    "%s: transited to non-PAUSE state\n", __func__);
1732 	}
1733 	if ((status & GEM_INTR_MIF) != 0)
1734 		device_printf(sc->sc_dev, "%s: MIF interrupt\n", __func__);
1735 #endif
1736 
1737 	if (__predict_false(status &
1738 	    (GEM_INTR_RX_TAG_ERR | GEM_INTR_PERR | GEM_INTR_BERR)) != 0)
1739 		gem_eint(sc, status);
1740 
1741 	if ((status & (GEM_INTR_RX_DONE | GEM_INTR_RX_NOBUF)) != 0)
1742 		gem_rint(sc);
1743 
1744 	if ((status & (GEM_INTR_TX_EMPTY | GEM_INTR_TX_INTME)) != 0)
1745 		gem_tint(sc);
1746 
1747 	if (__predict_false((status & GEM_INTR_TX_MAC) != 0)) {
1748 		status2 = GEM_BANK1_READ_4(sc, GEM_MAC_TX_STATUS);
1749 		if ((status2 &
1750 		    ~(GEM_MAC_TX_XMIT_DONE | GEM_MAC_TX_DEFER_EXP |
1751 		    GEM_MAC_TX_PEAK_EXP)) != 0)
1752 			device_printf(sc->sc_dev,
1753 			    "MAC TX fault, status %x\n", status2);
1754 		if ((status2 &
1755 		    (GEM_MAC_TX_UNDERRUN | GEM_MAC_TX_PKT_TOO_LONG)) != 0) {
1756 			sc->sc_ifp->if_oerrors++;
1757 			gem_init_locked(sc);
1758 		}
1759 	}
1760 	if (__predict_false((status & GEM_INTR_RX_MAC) != 0)) {
1761 		status2 = GEM_BANK1_READ_4(sc, GEM_MAC_RX_STATUS);
1762 		/*
1763 		 * At least with GEM_SUN_GEM and some GEM_SUN_ERI
1764 		 * revisions GEM_MAC_RX_OVERFLOW happen often due to a
1765 		 * silicon bug so handle them silently.  Moreover, it's
1766 		 * likely that the receiver has hung so we reset it.
1767 		 */
1768 		if ((status2 & GEM_MAC_RX_OVERFLOW) != 0) {
1769 			sc->sc_ifp->if_ierrors++;
1770 			gem_reset_rxdma(sc);
1771 		} else if ((status2 &
1772 		    ~(GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT)) != 0)
1773 			device_printf(sc->sc_dev,
1774 			    "MAC RX fault, status %x\n", status2);
1775 	}
1776 	GEM_UNLOCK(sc);
1777 }
1778 
1779 static int
1780 gem_watchdog(struct gem_softc *sc)
1781 {
1782 	struct ifnet *ifp = sc->sc_ifp;
1783 
1784 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1785 
1786 #ifdef GEM_DEBUG
1787 	CTR4(KTR_GEM,
1788 	    "%s: GEM_RX_CONFIG %x GEM_MAC_RX_STATUS %x GEM_MAC_RX_CONFIG %x",
1789 	    __func__, GEM_BANK1_READ_4(sc, GEM_RX_CONFIG),
1790 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_STATUS),
1791 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG));
1792 	CTR4(KTR_GEM,
1793 	    "%s: GEM_TX_CONFIG %x GEM_MAC_TX_STATUS %x GEM_MAC_TX_CONFIG %x",
1794 	    __func__, GEM_BANK1_READ_4(sc, GEM_TX_CONFIG),
1795 	    GEM_BANK1_READ_4(sc, GEM_MAC_TX_STATUS),
1796 	    GEM_BANK1_READ_4(sc, GEM_MAC_TX_CONFIG));
1797 #endif
1798 
1799 	if (sc->sc_wdog_timer == 0 || --sc->sc_wdog_timer != 0)
1800 		return (0);
1801 
1802 	if ((sc->sc_flags & GEM_LINK) != 0)
1803 		device_printf(sc->sc_dev, "device timeout\n");
1804 	else if (bootverbose)
1805 		device_printf(sc->sc_dev, "device timeout (no link)\n");
1806 	++ifp->if_oerrors;
1807 
1808 	/* Try to get more packets going. */
1809 	gem_init_locked(sc);
1810 	gem_start_locked(ifp);
1811 	return (EJUSTRETURN);
1812 }
1813 
1814 static void
1815 gem_mifinit(struct gem_softc *sc)
1816 {
1817 
1818 	/* Configure the MIF in frame mode. */
1819 	GEM_BANK1_WRITE_4(sc, GEM_MIF_CONFIG,
1820 	    GEM_BANK1_READ_4(sc, GEM_MIF_CONFIG) & ~GEM_MIF_CONFIG_BB_ENA);
1821 	GEM_BANK1_BARRIER(sc, GEM_MIF_CONFIG, 4,
1822 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1823 }
1824 
1825 /*
1826  * MII interface
1827  *
1828  * The MII interface supports at least three different operating modes:
1829  *
1830  * Bitbang mode is implemented using data, clock and output enable registers.
1831  *
1832  * Frame mode is implemented by loading a complete frame into the frame
1833  * register and polling the valid bit for completion.
1834  *
1835  * Polling mode uses the frame register but completion is indicated by
1836  * an interrupt.
1837  *
1838  */
1839 int
1840 gem_mii_readreg(device_t dev, int phy, int reg)
1841 {
1842 	struct gem_softc *sc;
1843 	int n;
1844 	uint32_t v;
1845 
1846 #ifdef GEM_DEBUG_PHY
1847 	printf("%s: phy %d reg %d\n", __func__, phy, reg);
1848 #endif
1849 
1850 	sc = device_get_softc(dev);
1851 	if (sc->sc_phyad != -1 && phy != sc->sc_phyad)
1852 		return (0);
1853 
1854 	if ((sc->sc_flags & GEM_SERDES) != 0) {
1855 		switch (reg) {
1856 		case MII_BMCR:
1857 			reg = GEM_MII_CONTROL;
1858 			break;
1859 		case MII_BMSR:
1860 			reg = GEM_MII_STATUS;
1861 			break;
1862 		case MII_PHYIDR1:
1863 		case MII_PHYIDR2:
1864 			return (0);
1865 		case MII_ANAR:
1866 			reg = GEM_MII_ANAR;
1867 			break;
1868 		case MII_ANLPAR:
1869 			reg = GEM_MII_ANLPAR;
1870 			break;
1871 		case MII_EXTSR:
1872 			return (EXTSR_1000XFDX | EXTSR_1000XHDX);
1873 		default:
1874 			device_printf(sc->sc_dev,
1875 			    "%s: unhandled register %d\n", __func__, reg);
1876 			return (0);
1877 		}
1878 		return (GEM_BANK1_READ_4(sc, reg));
1879 	}
1880 
1881 	/* Construct the frame command. */
1882 	v = GEM_MIF_FRAME_READ |
1883 	    (phy << GEM_MIF_PHY_SHIFT) |
1884 	    (reg << GEM_MIF_REG_SHIFT);
1885 
1886 	GEM_BANK1_WRITE_4(sc, GEM_MIF_FRAME, v);
1887 	GEM_BANK1_BARRIER(sc, GEM_MIF_FRAME, 4,
1888 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1889 	for (n = 0; n < 100; n++) {
1890 		DELAY(1);
1891 		v = GEM_BANK1_READ_4(sc, GEM_MIF_FRAME);
1892 		if (v & GEM_MIF_FRAME_TA0)
1893 			return (v & GEM_MIF_FRAME_DATA);
1894 	}
1895 
1896 	device_printf(sc->sc_dev, "%s: timed out\n", __func__);
1897 	return (0);
1898 }
1899 
1900 int
1901 gem_mii_writereg(device_t dev, int phy, int reg, int val)
1902 {
1903 	struct gem_softc *sc;
1904 	int n;
1905 	uint32_t v;
1906 
1907 #ifdef GEM_DEBUG_PHY
1908 	printf("%s: phy %d reg %d val %x\n", phy, reg, val, __func__);
1909 #endif
1910 
1911 	sc = device_get_softc(dev);
1912 	if (sc->sc_phyad != -1 && phy != sc->sc_phyad)
1913 		return (0);
1914 
1915 	if ((sc->sc_flags & GEM_SERDES) != 0) {
1916 		switch (reg) {
1917 		case MII_BMSR:
1918 			reg = GEM_MII_STATUS;
1919 			break;
1920 		case MII_BMCR:
1921 			reg = GEM_MII_CONTROL;
1922 			if ((val & GEM_MII_CONTROL_RESET) == 0)
1923 				break;
1924 			GEM_BANK1_WRITE_4(sc, GEM_MII_CONTROL, val);
1925 			GEM_BANK1_BARRIER(sc, GEM_MII_CONTROL, 4,
1926 			    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1927 			if (!GEM_BANK1_BITWAIT(sc, GEM_MII_CONTROL,
1928 			    GEM_MII_CONTROL_RESET, 0))
1929 				device_printf(sc->sc_dev,
1930 				    "cannot reset PCS\n");
1931 			/* FALLTHROUGH */
1932 		case MII_ANAR:
1933 			GEM_BANK1_WRITE_4(sc, GEM_MII_CONFIG, 0);
1934 			GEM_BANK1_BARRIER(sc, GEM_MII_CONFIG, 4,
1935 			    BUS_SPACE_BARRIER_WRITE);
1936 			GEM_BANK1_WRITE_4(sc, GEM_MII_ANAR, val);
1937 			GEM_BANK1_BARRIER(sc, GEM_MII_ANAR, 4,
1938 			    BUS_SPACE_BARRIER_WRITE);
1939 			GEM_BANK1_WRITE_4(sc, GEM_MII_SLINK_CONTROL,
1940 			    GEM_MII_SLINK_LOOPBACK | GEM_MII_SLINK_EN_SYNC_D);
1941 			GEM_BANK1_BARRIER(sc, GEM_MII_SLINK_CONTROL, 4,
1942 			    BUS_SPACE_BARRIER_WRITE);
1943 			GEM_BANK1_WRITE_4(sc, GEM_MII_CONFIG,
1944 			    GEM_MII_CONFIG_ENABLE);
1945 			GEM_BANK1_BARRIER(sc, GEM_MII_CONFIG, 4,
1946 			    BUS_SPACE_BARRIER_WRITE);
1947 			return (0);
1948 		case MII_ANLPAR:
1949 			reg = GEM_MII_ANLPAR;
1950 			break;
1951 		default:
1952 			device_printf(sc->sc_dev,
1953 			    "%s: unhandled register %d\n", __func__, reg);
1954 			return (0);
1955 		}
1956 		GEM_BANK1_WRITE_4(sc, reg, val);
1957 		GEM_BANK1_BARRIER(sc, reg, 4,
1958 		    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1959 		return (0);
1960 	}
1961 
1962 	/* Construct the frame command. */
1963 	v = GEM_MIF_FRAME_WRITE |
1964 	    (phy << GEM_MIF_PHY_SHIFT) |
1965 	    (reg << GEM_MIF_REG_SHIFT) |
1966 	    (val & GEM_MIF_FRAME_DATA);
1967 
1968 	GEM_BANK1_WRITE_4(sc, GEM_MIF_FRAME, v);
1969 	GEM_BANK1_BARRIER(sc, GEM_MIF_FRAME, 4,
1970 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1971 	for (n = 0; n < 100; n++) {
1972 		DELAY(1);
1973 		v = GEM_BANK1_READ_4(sc, GEM_MIF_FRAME);
1974 		if (v & GEM_MIF_FRAME_TA0)
1975 			return (1);
1976 	}
1977 
1978 	device_printf(sc->sc_dev, "%s: timed out\n", __func__);
1979 	return (0);
1980 }
1981 
1982 void
1983 gem_mii_statchg(device_t dev)
1984 {
1985 	struct gem_softc *sc;
1986 	int gigabit;
1987 	uint32_t rxcfg, txcfg, v;
1988 
1989 	sc = device_get_softc(dev);
1990 
1991 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1992 
1993 #ifdef GEM_DEBUG
1994 	if ((sc->sc_ifp->if_flags & IFF_DEBUG) != 0)
1995 		device_printf(sc->sc_dev, "%s: status change: PHY = %d\n",
1996 		    __func__, sc->sc_phyad);
1997 #endif
1998 
1999 	if ((sc->sc_mii->mii_media_status & IFM_ACTIVE) != 0 &&
2000 	    IFM_SUBTYPE(sc->sc_mii->mii_media_active) != IFM_NONE)
2001 		sc->sc_flags |= GEM_LINK;
2002 	else
2003 		sc->sc_flags &= ~GEM_LINK;
2004 
2005 	switch (IFM_SUBTYPE(sc->sc_mii->mii_media_active)) {
2006 	case IFM_1000_SX:
2007 	case IFM_1000_LX:
2008 	case IFM_1000_CX:
2009 	case IFM_1000_T:
2010 		gigabit = 1;
2011 		break;
2012 	default:
2013 		gigabit = 0;
2014 	}
2015 
2016 	/*
2017 	 * The configuration done here corresponds to the steps F) and
2018 	 * G) and as far as enabling of RX and TX MAC goes also step H)
2019 	 * of the initialization sequence outlined in section 3.2.1 of
2020 	 * the GEM Gigabit Ethernet ASIC Specification.
2021 	 */
2022 
2023 	rxcfg = GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG);
2024 	rxcfg &= ~(GEM_MAC_RX_CARR_EXTEND | GEM_MAC_RX_ENABLE);
2025 	txcfg = GEM_MAC_TX_ENA_IPG0 | GEM_MAC_TX_NGU | GEM_MAC_TX_NGU_LIMIT;
2026 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) != 0)
2027 		txcfg |= GEM_MAC_TX_IGN_CARRIER | GEM_MAC_TX_IGN_COLLIS;
2028 	else if (gigabit != 0) {
2029 		rxcfg |= GEM_MAC_RX_CARR_EXTEND;
2030 		txcfg |= GEM_MAC_TX_CARR_EXTEND;
2031 	}
2032 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG, 0);
2033 	GEM_BANK1_BARRIER(sc, GEM_MAC_TX_CONFIG, 4,
2034 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
2035 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0))
2036 		device_printf(sc->sc_dev, "cannot disable TX MAC\n");
2037 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG, txcfg);
2038 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, 0);
2039 	GEM_BANK1_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
2040 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
2041 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0))
2042 		device_printf(sc->sc_dev, "cannot disable RX MAC\n");
2043 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, rxcfg);
2044 
2045 	v = GEM_BANK1_READ_4(sc, GEM_MAC_CONTROL_CONFIG) &
2046 	    ~(GEM_MAC_CC_RX_PAUSE | GEM_MAC_CC_TX_PAUSE);
2047 #ifdef notyet
2048 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
2049 	    IFM_ETH_RXPAUSE) != 0)
2050 		v |= GEM_MAC_CC_RX_PAUSE;
2051 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
2052 	    IFM_ETH_TXPAUSE) != 0)
2053 		v |= GEM_MAC_CC_TX_PAUSE;
2054 #endif
2055 	GEM_BANK1_WRITE_4(sc, GEM_MAC_CONTROL_CONFIG, v);
2056 
2057 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) == 0 &&
2058 	    gigabit != 0)
2059 		GEM_BANK1_WRITE_4(sc, GEM_MAC_SLOT_TIME,
2060 		    GEM_MAC_SLOT_TIME_CARR_EXTEND);
2061 	else
2062 		GEM_BANK1_WRITE_4(sc, GEM_MAC_SLOT_TIME,
2063 		    GEM_MAC_SLOT_TIME_NORMAL);
2064 
2065 	/* XIF Configuration */
2066 	v = GEM_MAC_XIF_LINK_LED;
2067 	v |= GEM_MAC_XIF_TX_MII_ENA;
2068 	if ((sc->sc_flags & GEM_SERDES) == 0) {
2069 		if ((GEM_BANK1_READ_4(sc, GEM_MIF_CONFIG) &
2070 		    GEM_MIF_CONFIG_PHY_SEL) != 0) {
2071 			/* External MII needs echo disable if half duplex. */
2072 			if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
2073 			    IFM_FDX) == 0)
2074 				v |= GEM_MAC_XIF_ECHO_DISABL;
2075 		} else
2076 			/*
2077 			 * Internal MII needs buffer enable.
2078 			 * XXX buffer enable makes only sense for an
2079 			 * external PHY.
2080 			 */
2081 			v |= GEM_MAC_XIF_MII_BUF_ENA;
2082 	}
2083 	if (gigabit != 0)
2084 		v |= GEM_MAC_XIF_GMII_MODE;
2085 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) != 0)
2086 		v |= GEM_MAC_XIF_FDPLX_LED;
2087 	GEM_BANK1_WRITE_4(sc, GEM_MAC_XIF_CONFIG, v);
2088 
2089 	if ((sc->sc_ifp->if_drv_flags & IFF_DRV_RUNNING) != 0 &&
2090 	    (sc->sc_flags & GEM_LINK) != 0) {
2091 		GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG,
2092 		    txcfg | GEM_MAC_TX_ENABLE);
2093 		GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG,
2094 		    rxcfg | GEM_MAC_RX_ENABLE);
2095 	}
2096 }
2097 
2098 int
2099 gem_mediachange(struct ifnet *ifp)
2100 {
2101 	struct gem_softc *sc = ifp->if_softc;
2102 	int error;
2103 
2104 	/* XXX add support for serial media. */
2105 
2106 	GEM_LOCK(sc);
2107 	error = mii_mediachg(sc->sc_mii);
2108 	GEM_UNLOCK(sc);
2109 	return (error);
2110 }
2111 
2112 void
2113 gem_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
2114 {
2115 	struct gem_softc *sc = ifp->if_softc;
2116 
2117 	GEM_LOCK(sc);
2118 	if ((ifp->if_flags & IFF_UP) == 0) {
2119 		GEM_UNLOCK(sc);
2120 		return;
2121 	}
2122 
2123 	mii_pollstat(sc->sc_mii);
2124 	ifmr->ifm_active = sc->sc_mii->mii_media_active;
2125 	ifmr->ifm_status = sc->sc_mii->mii_media_status;
2126 	GEM_UNLOCK(sc);
2127 }
2128 
2129 static int
2130 gem_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
2131 {
2132 	struct gem_softc *sc = ifp->if_softc;
2133 	struct ifreq *ifr = (struct ifreq *)data;
2134 	int error;
2135 
2136 	error = 0;
2137 	switch (cmd) {
2138 	case SIOCSIFFLAGS:
2139 		GEM_LOCK(sc);
2140 		if ((ifp->if_flags & IFF_UP) != 0) {
2141 			if ((ifp->if_drv_flags & IFF_DRV_RUNNING) != 0 &&
2142 			    ((ifp->if_flags ^ sc->sc_ifflags) &
2143 			    (IFF_ALLMULTI | IFF_PROMISC)) != 0)
2144 				gem_setladrf(sc);
2145 			else
2146 				gem_init_locked(sc);
2147 		} else if ((ifp->if_drv_flags & IFF_DRV_RUNNING) != 0)
2148 			gem_stop(ifp, 0);
2149 		if ((ifp->if_flags & IFF_LINK0) != 0)
2150 			sc->sc_csum_features |= CSUM_UDP;
2151 		else
2152 			sc->sc_csum_features &= ~CSUM_UDP;
2153 		if ((ifp->if_capenable & IFCAP_TXCSUM) != 0)
2154 			ifp->if_hwassist = sc->sc_csum_features;
2155 		sc->sc_ifflags = ifp->if_flags;
2156 		GEM_UNLOCK(sc);
2157 		break;
2158 	case SIOCADDMULTI:
2159 	case SIOCDELMULTI:
2160 		GEM_LOCK(sc);
2161 		gem_setladrf(sc);
2162 		GEM_UNLOCK(sc);
2163 		break;
2164 	case SIOCGIFMEDIA:
2165 	case SIOCSIFMEDIA:
2166 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_mii->mii_media, cmd);
2167 		break;
2168 	case SIOCSIFCAP:
2169 		GEM_LOCK(sc);
2170 		ifp->if_capenable = ifr->ifr_reqcap;
2171 		if ((ifp->if_capenable & IFCAP_TXCSUM) != 0)
2172 			ifp->if_hwassist = sc->sc_csum_features;
2173 		else
2174 			ifp->if_hwassist = 0;
2175 		GEM_UNLOCK(sc);
2176 		break;
2177 	default:
2178 		error = ether_ioctl(ifp, cmd, data);
2179 		break;
2180 	}
2181 
2182 	return (error);
2183 }
2184 
2185 static void
2186 gem_setladrf(struct gem_softc *sc)
2187 {
2188 	struct ifnet *ifp = sc->sc_ifp;
2189 	struct ifmultiaddr *inm;
2190 	int i;
2191 	uint32_t hash[16];
2192 	uint32_t crc, v;
2193 
2194 	GEM_LOCK_ASSERT(sc, MA_OWNED);
2195 
2196 	/* Get the current RX configuration. */
2197 	v = GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG);
2198 
2199 	/*
2200 	 * Turn off promiscuous mode, promiscuous group mode (all multicast),
2201 	 * and hash filter.  Depending on the case, the right bit will be
2202 	 * enabled.
2203 	 */
2204 	v &= ~(GEM_MAC_RX_PROMISCUOUS | GEM_MAC_RX_HASH_FILTER |
2205 	    GEM_MAC_RX_PROMISC_GRP);
2206 
2207 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, v);
2208 	GEM_BANK1_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
2209 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
2210 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_HASH_FILTER,
2211 	    0))
2212 		device_printf(sc->sc_dev, "cannot disable RX hash filter\n");
2213 
2214 	if ((ifp->if_flags & IFF_PROMISC) != 0) {
2215 		v |= GEM_MAC_RX_PROMISCUOUS;
2216 		goto chipit;
2217 	}
2218 	if ((ifp->if_flags & IFF_ALLMULTI) != 0) {
2219 		v |= GEM_MAC_RX_PROMISC_GRP;
2220 		goto chipit;
2221 	}
2222 
2223 	/*
2224 	 * Set up multicast address filter by passing all multicast
2225 	 * addresses through a crc generator, and then using the high
2226 	 * order 8 bits as an index into the 256 bit logical address
2227 	 * filter.  The high order 4 bits selects the word, while the
2228 	 * other 4 bits select the bit within the word (where bit 0
2229 	 * is the MSB).
2230 	 */
2231 
2232 	/* Clear the hash table. */
2233 	memset(hash, 0, sizeof(hash));
2234 
2235 	if_maddr_rlock(ifp);
2236 	TAILQ_FOREACH(inm, &ifp->if_multiaddrs, ifma_link) {
2237 		if (inm->ifma_addr->sa_family != AF_LINK)
2238 			continue;
2239 		crc = ether_crc32_le(LLADDR((struct sockaddr_dl *)
2240 		    inm->ifma_addr), ETHER_ADDR_LEN);
2241 
2242 		/* We just want the 8 most significant bits. */
2243 		crc >>= 24;
2244 
2245 		/* Set the corresponding bit in the filter. */
2246 		hash[crc >> 4] |= 1 << (15 - (crc & 15));
2247 	}
2248 	if_maddr_runlock(ifp);
2249 
2250 	v |= GEM_MAC_RX_HASH_FILTER;
2251 
2252 	/* Now load the hash table into the chip (if we are using it). */
2253 	for (i = 0; i < 16; i++)
2254 		GEM_BANK1_WRITE_4(sc,
2255 		    GEM_MAC_HASH0 + i * (GEM_MAC_HASH1 - GEM_MAC_HASH0),
2256 		    hash[i]);
2257 
2258  chipit:
2259 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, v);
2260 }
2261