xref: /freebsd/sys/dev/gem/if_gem.c (revision 721351876cd4d3a8a700f62d2061331fa951a488)
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	TRIES	10000
88 
89 /*
90  * The GEM hardware support 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 int	gem_watchdog(struct gem_softc *sc);
131 
132 devclass_t gem_devclass;
133 DRIVER_MODULE(miibus, gem, miibus_driver, miibus_devclass, 0, 0);
134 MODULE_DEPEND(gem, miibus, 1, 1, 1);
135 
136 #ifdef GEM_DEBUG
137 #include <sys/ktr.h>
138 #define	KTR_GEM		KTR_CT2
139 #endif
140 
141 #define	GEM_BANK1_BITWAIT(sc, r, clr, set)				\
142 	gem_bitwait((sc), GEM_RES_BANK1, (r), (clr), (set))
143 #define	GEM_BANK2_BITWAIT(sc, r, clr, set)				\
144 	gem_bitwait((sc), GEM_RES_BANK2, (r), (clr), (set))
145 
146 int
147 gem_attach(struct gem_softc *sc)
148 {
149 	struct gem_txsoft *txs;
150 	struct ifnet *ifp;
151 	int error, i;
152 	uint32_t v;
153 
154 	ifp = sc->sc_ifp = if_alloc(IFT_ETHER);
155 	if (ifp == NULL)
156 		return (ENOSPC);
157 
158 	callout_init_mtx(&sc->sc_tick_ch, &sc->sc_mtx, 0);
159 #ifdef GEM_RINT_TIMEOUT
160 	callout_init_mtx(&sc->sc_rx_ch, &sc->sc_mtx, 0);
161 #endif
162 
163 	/* Make sure the chip is stopped. */
164 	ifp->if_softc = sc;
165 	gem_reset(sc);
166 
167 	error = bus_dma_tag_create(bus_get_dma_tag(sc->sc_dev), 1, 0,
168 	    BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
169 	    BUS_SPACE_MAXSIZE_32BIT, 0, BUS_SPACE_MAXSIZE_32BIT, 0, NULL,
170 	    NULL, &sc->sc_pdmatag);
171 	if (error)
172 		goto fail_ifnet;
173 
174 	error = bus_dma_tag_create(sc->sc_pdmatag, 1, 0,
175 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL, MCLBYTES,
176 	    1, MCLBYTES, BUS_DMA_ALLOCNOW, NULL, NULL, &sc->sc_rdmatag);
177 	if (error)
178 		goto fail_ptag;
179 
180 	error = bus_dma_tag_create(sc->sc_pdmatag, 1, 0,
181 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
182 	    MCLBYTES * GEM_NTXSEGS, GEM_NTXSEGS, MCLBYTES,
183 	    BUS_DMA_ALLOCNOW, NULL, NULL, &sc->sc_tdmatag);
184 	if (error)
185 		goto fail_rtag;
186 
187 	error = bus_dma_tag_create(sc->sc_pdmatag, PAGE_SIZE, 0,
188 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
189 	    sizeof(struct gem_control_data), 1,
190 	    sizeof(struct gem_control_data), 0,
191 	    NULL, NULL, &sc->sc_cdmatag);
192 	if (error)
193 		goto fail_ttag;
194 
195 	/*
196 	 * Allocate the control data structures, create and load the
197 	 * DMA map for it.
198 	 */
199 	if ((error = bus_dmamem_alloc(sc->sc_cdmatag,
200 	    (void **)&sc->sc_control_data,
201 	    BUS_DMA_WAITOK | BUS_DMA_COHERENT | BUS_DMA_ZERO,
202 	    &sc->sc_cddmamap))) {
203 		device_printf(sc->sc_dev,
204 		    "unable to allocate control data, error = %d\n", error);
205 		goto fail_ctag;
206 	}
207 
208 	sc->sc_cddma = 0;
209 	if ((error = bus_dmamap_load(sc->sc_cdmatag, sc->sc_cddmamap,
210 	    sc->sc_control_data, sizeof(struct gem_control_data),
211 	    gem_cddma_callback, sc, 0)) != 0 || sc->sc_cddma == 0) {
212 		device_printf(sc->sc_dev,
213 		    "unable to load control data DMA map, error = %d\n",
214 		    error);
215 		goto fail_cmem;
216 	}
217 
218 	/*
219 	 * Initialize the transmit job descriptors.
220 	 */
221 	STAILQ_INIT(&sc->sc_txfreeq);
222 	STAILQ_INIT(&sc->sc_txdirtyq);
223 
224 	/*
225 	 * Create the transmit buffer DMA maps.
226 	 */
227 	error = ENOMEM;
228 	for (i = 0; i < GEM_TXQUEUELEN; i++) {
229 		txs = &sc->sc_txsoft[i];
230 		txs->txs_mbuf = NULL;
231 		txs->txs_ndescs = 0;
232 		if ((error = bus_dmamap_create(sc->sc_tdmatag, 0,
233 		    &txs->txs_dmamap)) != 0) {
234 			device_printf(sc->sc_dev,
235 			    "unable to create TX DMA map %d, error = %d\n",
236 			    i, error);
237 			goto fail_txd;
238 		}
239 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
240 	}
241 
242 	/*
243 	 * Create the receive buffer DMA maps.
244 	 */
245 	for (i = 0; i < GEM_NRXDESC; i++) {
246 		if ((error = bus_dmamap_create(sc->sc_rdmatag, 0,
247 		    &sc->sc_rxsoft[i].rxs_dmamap)) != 0) {
248 			device_printf(sc->sc_dev,
249 			    "unable to create RX DMA map %d, error = %d\n",
250 			    i, error);
251 			goto fail_rxd;
252 		}
253 		sc->sc_rxsoft[i].rxs_mbuf = NULL;
254 	}
255 
256 	/* Bad things will happen when touching this register on ERI. */
257 	if (sc->sc_variant != GEM_SUN_ERI)
258 		GEM_BANK1_WRITE_4(sc, GEM_MII_DATAPATH_MODE,
259 		    GEM_MII_DATAPATH_MII);
260 
261 	gem_mifinit(sc);
262 
263 	/*
264 	 * Look for an external PHY.
265 	 */
266 	error = ENXIO;
267 	v = GEM_BANK1_READ_4(sc, GEM_MIF_CONFIG);
268 	if ((v & GEM_MIF_CONFIG_MDI1) != 0) {
269 		v |= GEM_MIF_CONFIG_PHY_SEL;
270 		GEM_BANK1_WRITE_4(sc, GEM_MIF_CONFIG, v);
271 		switch (sc->sc_variant) {
272 		case GEM_SUN_ERI:
273 			sc->sc_phyad = GEM_PHYAD_EXTERNAL;
274 			break;
275 		default:
276 			sc->sc_phyad = -1;
277 			break;
278 		}
279 		error = mii_phy_probe(sc->sc_dev, &sc->sc_miibus,
280 		    gem_mediachange, gem_mediastatus);
281 	}
282 
283 	/*
284 	 * Fall back on an internal PHY if no external PHY was found.
285 	 */
286 	if (error != 0 && (v & GEM_MIF_CONFIG_MDI0) != 0) {
287 		v &= ~GEM_MIF_CONFIG_PHY_SEL;
288 		GEM_BANK1_WRITE_4(sc, GEM_MIF_CONFIG, v);
289 		switch (sc->sc_variant) {
290 		case GEM_SUN_ERI:
291 		case GEM_APPLE_K2_GMAC:
292 			sc->sc_phyad = GEM_PHYAD_INTERNAL;
293 			break;
294 		case GEM_APPLE_GMAC:
295 			sc->sc_phyad = GEM_PHYAD_EXTERNAL;
296 			break;
297 		default:
298 			sc->sc_phyad = -1;
299 			break;
300 		}
301 		error = mii_phy_probe(sc->sc_dev, &sc->sc_miibus,
302 		    gem_mediachange, gem_mediastatus);
303 	}
304 
305 	/*
306 	 * Try the external PCS SERDES if we didn't find any PHYs.
307 	 */
308 	if (error != 0 && sc->sc_variant == GEM_SUN_GEM) {
309 		GEM_BANK1_WRITE_4(sc, GEM_MII_DATAPATH_MODE,
310 		    GEM_MII_DATAPATH_SERDES);
311 		GEM_BANK1_WRITE_4(sc, GEM_MII_SLINK_CONTROL,
312 		    GEM_MII_SLINK_LOOPBACK | GEM_MII_SLINK_EN_SYNC_D);
313 		GEM_BANK1_WRITE_4(sc, GEM_MII_CONFIG, GEM_MII_CONFIG_ENABLE);
314 		sc->sc_flags |= GEM_SERDES;
315 		sc->sc_phyad = GEM_PHYAD_EXTERNAL;
316 		error = mii_phy_probe(sc->sc_dev, &sc->sc_miibus,
317 		    gem_mediachange, gem_mediastatus);
318 	}
319 
320 	if (error != 0) {
321 		device_printf(sc->sc_dev, "PHY probe failed: %d\n", error);
322 		goto fail_rxd;
323 	}
324 	sc->sc_mii = device_get_softc(sc->sc_miibus);
325 
326 	/*
327 	 * From this point forward, the attachment cannot fail.  A failure
328 	 * before this point releases all resources that may have been
329 	 * allocated.
330 	 */
331 
332 	/* Get RX FIFO size. */
333 	sc->sc_rxfifosize = 64 *
334 	    GEM_BANK1_READ_4(sc, GEM_RX_FIFO_SIZE);
335 
336 	/* Get TX FIFO size. */
337 	v = GEM_BANK1_READ_4(sc, GEM_TX_FIFO_SIZE);
338 	device_printf(sc->sc_dev, "%ukB RX FIFO, %ukB TX FIFO\n",
339 	    sc->sc_rxfifosize / 1024, v / 16);
340 
341 	sc->sc_csum_features = GEM_CSUM_FEATURES;
342 	/* Initialize ifnet structure. */
343 	ifp->if_softc = sc;
344 	if_initname(ifp, device_get_name(sc->sc_dev),
345 	    device_get_unit(sc->sc_dev));
346 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
347 	ifp->if_start = gem_start;
348 	ifp->if_ioctl = gem_ioctl;
349 	ifp->if_init = gem_init;
350 	IFQ_SET_MAXLEN(&ifp->if_snd, GEM_TXQUEUELEN);
351 	ifp->if_snd.ifq_drv_maxlen = GEM_TXQUEUELEN;
352 	IFQ_SET_READY(&ifp->if_snd);
353 
354 	/* Attach the interface. */
355 	ether_ifattach(ifp, sc->sc_enaddr);
356 
357 	/*
358 	 * Tell the upper layer(s) we support long frames/checksum offloads.
359 	 */
360 	ifp->if_data.ifi_hdrlen = sizeof(struct ether_vlan_header);
361 	ifp->if_capabilities |= IFCAP_VLAN_MTU | IFCAP_HWCSUM;
362 	ifp->if_hwassist |= sc->sc_csum_features;
363 	ifp->if_capenable |= IFCAP_VLAN_MTU | IFCAP_HWCSUM;
364 
365 	return (0);
366 
367 	/*
368 	 * Free any resources we've allocated during the failed attach
369 	 * attempt.  Do this in reverse order and fall through.
370 	 */
371  fail_rxd:
372 	for (i = 0; i < GEM_NRXDESC; i++)
373 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
374 			bus_dmamap_destroy(sc->sc_rdmatag,
375 			    sc->sc_rxsoft[i].rxs_dmamap);
376  fail_txd:
377 	for (i = 0; i < GEM_TXQUEUELEN; i++)
378 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
379 			bus_dmamap_destroy(sc->sc_tdmatag,
380 			    sc->sc_txsoft[i].txs_dmamap);
381 	bus_dmamap_unload(sc->sc_cdmatag, sc->sc_cddmamap);
382  fail_cmem:
383 	bus_dmamem_free(sc->sc_cdmatag, sc->sc_control_data,
384 	    sc->sc_cddmamap);
385  fail_ctag:
386 	bus_dma_tag_destroy(sc->sc_cdmatag);
387  fail_ttag:
388 	bus_dma_tag_destroy(sc->sc_tdmatag);
389  fail_rtag:
390 	bus_dma_tag_destroy(sc->sc_rdmatag);
391  fail_ptag:
392 	bus_dma_tag_destroy(sc->sc_pdmatag);
393  fail_ifnet:
394 	if_free(ifp);
395 	return (error);
396 }
397 
398 void
399 gem_detach(struct gem_softc *sc)
400 {
401 	struct ifnet *ifp = sc->sc_ifp;
402 	int i;
403 
404 	GEM_LOCK(sc);
405 	gem_stop(ifp, 1);
406 	GEM_UNLOCK(sc);
407 	callout_drain(&sc->sc_tick_ch);
408 #ifdef GEM_RINT_TIMEOUT
409 	callout_drain(&sc->sc_rx_ch);
410 #endif
411 	ether_ifdetach(ifp);
412 	if_free(ifp);
413 	device_delete_child(sc->sc_dev, sc->sc_miibus);
414 
415 	for (i = 0; i < GEM_NRXDESC; i++)
416 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
417 			bus_dmamap_destroy(sc->sc_rdmatag,
418 			    sc->sc_rxsoft[i].rxs_dmamap);
419 	for (i = 0; i < GEM_TXQUEUELEN; i++)
420 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
421 			bus_dmamap_destroy(sc->sc_tdmatag,
422 			    sc->sc_txsoft[i].txs_dmamap);
423 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
424 	bus_dmamap_unload(sc->sc_cdmatag, sc->sc_cddmamap);
425 	bus_dmamem_free(sc->sc_cdmatag, sc->sc_control_data,
426 	    sc->sc_cddmamap);
427 	bus_dma_tag_destroy(sc->sc_cdmatag);
428 	bus_dma_tag_destroy(sc->sc_tdmatag);
429 	bus_dma_tag_destroy(sc->sc_rdmatag);
430 	bus_dma_tag_destroy(sc->sc_pdmatag);
431 }
432 
433 void
434 gem_suspend(struct gem_softc *sc)
435 {
436 	struct ifnet *ifp = sc->sc_ifp;
437 
438 	GEM_LOCK(sc);
439 	gem_stop(ifp, 0);
440 	GEM_UNLOCK(sc);
441 }
442 
443 void
444 gem_resume(struct gem_softc *sc)
445 {
446 	struct ifnet *ifp = sc->sc_ifp;
447 
448 	GEM_LOCK(sc);
449 	/*
450 	 * On resume all registers have to be initialized again like
451 	 * after power-on.
452 	 */
453 	sc->sc_flags &= ~GEM_INITED;
454 	if (ifp->if_flags & IFF_UP)
455 		gem_init_locked(sc);
456 	GEM_UNLOCK(sc);
457 }
458 
459 static __inline void
460 gem_rxcksum(struct mbuf *m, uint64_t flags)
461 {
462 	struct ether_header *eh;
463 	struct ip *ip;
464 	struct udphdr *uh;
465 	uint16_t *opts;
466 	int32_t hlen, len, pktlen;
467 	uint32_t temp32;
468 	uint16_t cksum;
469 
470 	pktlen = m->m_pkthdr.len;
471 	if (pktlen < sizeof(struct ether_header) + sizeof(struct ip))
472 		return;
473 	eh = mtod(m, struct ether_header *);
474 	if (eh->ether_type != htons(ETHERTYPE_IP))
475 		return;
476 	ip = (struct ip *)(eh + 1);
477 	if (ip->ip_v != IPVERSION)
478 		return;
479 
480 	hlen = ip->ip_hl << 2;
481 	pktlen -= sizeof(struct ether_header);
482 	if (hlen < sizeof(struct ip))
483 		return;
484 	if (ntohs(ip->ip_len) < hlen)
485 		return;
486 	if (ntohs(ip->ip_len) != pktlen)
487 		return;
488 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK))
489 		return;	/* Cannot handle fragmented packet. */
490 
491 	switch (ip->ip_p) {
492 	case IPPROTO_TCP:
493 		if (pktlen < (hlen + sizeof(struct tcphdr)))
494 			return;
495 		break;
496 	case IPPROTO_UDP:
497 		if (pktlen < (hlen + sizeof(struct udphdr)))
498 			return;
499 		uh = (struct udphdr *)((uint8_t *)ip + hlen);
500 		if (uh->uh_sum == 0)
501 			return; /* no checksum */
502 		break;
503 	default:
504 		return;
505 	}
506 
507 	cksum = ~(flags & GEM_RD_CHECKSUM);
508 	/* checksum fixup for IP options */
509 	len = hlen - sizeof(struct ip);
510 	if (len > 0) {
511 		opts = (uint16_t *)(ip + 1);
512 		for (; len > 0; len -= sizeof(uint16_t), opts++) {
513 			temp32 = cksum - *opts;
514 			temp32 = (temp32 >> 16) + (temp32 & 65535);
515 			cksum = temp32 & 65535;
516 		}
517 	}
518 	m->m_pkthdr.csum_flags |= CSUM_DATA_VALID;
519 	m->m_pkthdr.csum_data = cksum;
520 }
521 
522 static void
523 gem_cddma_callback(void *xsc, bus_dma_segment_t *segs, int nsegs, int error)
524 {
525 	struct gem_softc *sc = xsc;
526 
527 	if (error != 0)
528 		return;
529 	if (nsegs != 1)
530 		panic("%s: bad control buffer segment count", __func__);
531 	sc->sc_cddma = segs[0].ds_addr;
532 }
533 
534 static void
535 gem_tick(void *arg)
536 {
537 	struct gem_softc *sc = arg;
538 	struct ifnet *ifp;
539 
540 	GEM_LOCK_ASSERT(sc, MA_OWNED);
541 
542 	ifp = sc->sc_ifp;
543 	/*
544 	 * Unload collision counters.
545 	 */
546 	ifp->if_collisions +=
547 	    GEM_BANK1_READ_4(sc, GEM_MAC_NORM_COLL_CNT) +
548 	    GEM_BANK1_READ_4(sc, GEM_MAC_FIRST_COLL_CNT) +
549 	    GEM_BANK1_READ_4(sc, GEM_MAC_EXCESS_COLL_CNT) +
550 	    GEM_BANK1_READ_4(sc, GEM_MAC_LATE_COLL_CNT);
551 
552 	/*
553 	 * Then clear the hardware counters.
554 	 */
555 	GEM_BANK1_WRITE_4(sc, GEM_MAC_NORM_COLL_CNT, 0);
556 	GEM_BANK1_WRITE_4(sc, GEM_MAC_FIRST_COLL_CNT, 0);
557 	GEM_BANK1_WRITE_4(sc, GEM_MAC_EXCESS_COLL_CNT, 0);
558 	GEM_BANK1_WRITE_4(sc, GEM_MAC_LATE_COLL_CNT, 0);
559 
560 	mii_tick(sc->sc_mii);
561 
562 	if (gem_watchdog(sc) == EJUSTRETURN)
563 		return;
564 
565 	callout_reset(&sc->sc_tick_ch, hz, gem_tick, sc);
566 }
567 
568 static int
569 gem_bitwait(struct gem_softc *sc, u_int bank, bus_addr_t r, uint32_t clr,
570     uint32_t set)
571 {
572 	int i;
573 	uint32_t reg;
574 
575 	for (i = TRIES; i--; DELAY(100)) {
576 		reg = GEM_BANKN_READ_M(bank, 4, sc, r);
577 		if ((reg & clr) == 0 && (reg & set) == set)
578 			return (1);
579 	}
580 	return (0);
581 }
582 
583 static void
584 gem_reset(sc)
585 	struct gem_softc *sc;
586 {
587 
588 #ifdef GEM_DEBUG
589 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
590 #endif
591 	gem_reset_rx(sc);
592 	gem_reset_tx(sc);
593 
594 	/* Do a full reset. */
595 	GEM_BANK2_WRITE_4(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX);
596 	GEM_BANK2_BARRIER(sc, GEM_RESET, 4,
597 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
598 	if (!GEM_BANK2_BITWAIT(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX, 0))
599 		device_printf(sc->sc_dev, "cannot reset device\n");
600 }
601 
602 static void
603 gem_rxdrain(struct gem_softc *sc)
604 {
605 	struct gem_rxsoft *rxs;
606 	int i;
607 
608 	for (i = 0; i < GEM_NRXDESC; i++) {
609 		rxs = &sc->sc_rxsoft[i];
610 		if (rxs->rxs_mbuf != NULL) {
611 			bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
612 			    BUS_DMASYNC_POSTREAD);
613 			bus_dmamap_unload(sc->sc_rdmatag, rxs->rxs_dmamap);
614 			m_freem(rxs->rxs_mbuf);
615 			rxs->rxs_mbuf = NULL;
616 		}
617 	}
618 }
619 
620 static void
621 gem_stop(struct ifnet *ifp, int disable)
622 {
623 	struct gem_softc *sc = ifp->if_softc;
624 	struct gem_txsoft *txs;
625 
626 #ifdef GEM_DEBUG
627 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
628 #endif
629 
630 	callout_stop(&sc->sc_tick_ch);
631 #ifdef GEM_RINT_TIMEOUT
632 	callout_stop(&sc->sc_rx_ch);
633 #endif
634 
635 	/* XXX should we reset these instead? */
636 	gem_disable_tx(sc);
637 	gem_disable_rx(sc);
638 
639 	/*
640 	 * Release any queued transmit buffers.
641 	 */
642 	while ((txs = STAILQ_FIRST(&sc->sc_txdirtyq)) != NULL) {
643 		STAILQ_REMOVE_HEAD(&sc->sc_txdirtyq, txs_q);
644 		if (txs->txs_ndescs != 0) {
645 			bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
646 			    BUS_DMASYNC_POSTWRITE);
647 			bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
648 			if (txs->txs_mbuf != NULL) {
649 				m_freem(txs->txs_mbuf);
650 				txs->txs_mbuf = NULL;
651 			}
652 		}
653 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
654 	}
655 
656 	if (disable)
657 		gem_rxdrain(sc);
658 
659 	/*
660 	 * Mark the interface down and cancel the watchdog timer.
661 	 */
662 	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
663 	sc->sc_flags &= ~GEM_LINK;
664 	sc->sc_wdog_timer = 0;
665 }
666 
667 static int
668 gem_reset_rx(struct gem_softc *sc)
669 {
670 
671 	/*
672 	 * Resetting while DMA is in progress can cause a bus hang, so we
673 	 * disable DMA first.
674 	 */
675 	gem_disable_rx(sc);
676 	GEM_BANK1_WRITE_4(sc, GEM_RX_CONFIG, 0);
677 	GEM_BANK1_BARRIER(sc, GEM_RX_CONFIG, 4,
678 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
679 	if (!GEM_BANK1_BITWAIT(sc, GEM_RX_CONFIG, GEM_RX_CONFIG_RXDMA_EN, 0))
680 		device_printf(sc->sc_dev, "cannot disable RX DMA\n");
681 
682 	/* Finally, reset the ERX. */
683 	GEM_BANK2_WRITE_4(sc, GEM_RESET, GEM_RESET_RX);
684 	GEM_BANK2_BARRIER(sc, GEM_RESET, 4,
685 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
686 	if (!GEM_BANK2_BITWAIT(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX,
687 	    0)) {
688 		device_printf(sc->sc_dev, "cannot reset receiver\n");
689 		return (1);
690 	}
691 	return (0);
692 }
693 
694 /*
695  * Reset the receiver DMA engine.
696  *
697  * Intended to be used in case of GEM_INTR_RX_TAG_ERR, GEM_MAC_RX_OVERFLOW
698  * etc in order to reset the receiver DMA engine only and not do a full
699  * reset which amongst others also downs the link and clears the FIFOs.
700  */
701 static void
702 gem_reset_rxdma(struct gem_softc *sc)
703 {
704 	int i;
705 
706 	if (gem_reset_rx(sc) != 0)
707 		return (gem_init_locked(sc));
708 	for (i = 0; i < GEM_NRXDESC; i++)
709 		if (sc->sc_rxsoft[i].rxs_mbuf != NULL)
710 			GEM_UPDATE_RXDESC(sc, i);
711 	sc->sc_rxptr = 0;
712 	GEM_CDSYNC(sc, BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD);
713 
714 	/* NOTE: we use only 32-bit DMA addresses here. */
715 	GEM_BANK1_WRITE_4(sc, GEM_RX_RING_PTR_HI, 0);
716 	GEM_BANK1_WRITE_4(sc, GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
717 	GEM_BANK1_WRITE_4(sc, GEM_RX_KICK, GEM_NRXDESC - 4);
718 	GEM_BANK1_WRITE_4(sc, GEM_RX_CONFIG,
719 	    gem_ringsize(GEM_NRXDESC /* XXX */) |
720 	    ((ETHER_HDR_LEN + sizeof(struct ip)) <<
721 	    GEM_RX_CONFIG_CXM_START_SHFT) |
722 	    (GEM_THRSH_1024 << GEM_RX_CONFIG_FIFO_THRS_SHIFT) |
723 	    (2 << GEM_RX_CONFIG_FBOFF_SHFT));
724 	GEM_BANK1_WRITE_4(sc, GEM_RX_BLANKING,
725 	    (6 << GEM_RX_BLANKING_TIME_SHIFT) | 6);
726 	GEM_BANK1_WRITE_4(sc, GEM_RX_PAUSE_THRESH,
727 	    (3 * sc->sc_rxfifosize / 256) |
728 	    ((sc->sc_rxfifosize / 256) << 12));
729 	GEM_BANK1_WRITE_4(sc, GEM_RX_CONFIG,
730 	    GEM_BANK1_READ_4(sc, GEM_RX_CONFIG) | GEM_RX_CONFIG_RXDMA_EN);
731 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_MASK,
732 	    GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT);
733 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG,
734 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG) | GEM_MAC_RX_ENABLE);
735 }
736 
737 static int
738 gem_reset_tx(struct gem_softc *sc)
739 {
740 
741 	/*
742 	 * Resetting while DMA is in progress can cause a bus hang, so we
743 	 * disable DMA first.
744 	 */
745 	gem_disable_tx(sc);
746 	GEM_BANK1_WRITE_4(sc, GEM_TX_CONFIG, 0);
747 	GEM_BANK1_BARRIER(sc, GEM_TX_CONFIG, 4,
748 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
749 	if (!GEM_BANK1_BITWAIT(sc, GEM_TX_CONFIG, GEM_TX_CONFIG_TXDMA_EN, 0))
750 		device_printf(sc->sc_dev, "cannot disable TX DMA\n");
751 
752 	/* Finally, reset the ETX. */
753 	GEM_BANK2_WRITE_4(sc, GEM_RESET, GEM_RESET_TX);
754 	GEM_BANK2_BARRIER(sc, GEM_RESET, 4,
755 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
756 	if (!GEM_BANK2_BITWAIT(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX,
757 	    0)) {
758 		device_printf(sc->sc_dev, "cannot reset transmitter\n");
759 		return (1);
760 	}
761 	return (0);
762 }
763 
764 static int
765 gem_disable_rx(struct gem_softc *sc)
766 {
767 
768 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG,
769 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG) & ~GEM_MAC_RX_ENABLE);
770 	GEM_BANK1_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
771 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
772 	return (GEM_BANK1_BITWAIT(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE,
773 	    0));
774 }
775 
776 static int
777 gem_disable_tx(struct gem_softc *sc)
778 {
779 
780 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG,
781 	    GEM_BANK1_READ_4(sc, GEM_MAC_TX_CONFIG) & ~GEM_MAC_TX_ENABLE);
782 	GEM_BANK1_BARRIER(sc, GEM_MAC_TX_CONFIG, 4,
783 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
784 	return (GEM_BANK1_BITWAIT(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE,
785 	    0));
786 }
787 
788 static int
789 gem_meminit(sc)
790 	struct gem_softc *sc;
791 {
792 	struct gem_rxsoft *rxs;
793 	int error, i;
794 
795 	/*
796 	 * Initialize the transmit descriptor ring.
797 	 */
798 	for (i = 0; i < GEM_NTXDESC; i++) {
799 		sc->sc_txdescs[i].gd_flags = 0;
800 		sc->sc_txdescs[i].gd_addr = 0;
801 	}
802 	sc->sc_txfree = GEM_MAXTXFREE;
803 	sc->sc_txnext = 0;
804 	sc->sc_txwin = 0;
805 
806 	/*
807 	 * Initialize the receive descriptor and receive job
808 	 * descriptor rings.
809 	 */
810 	for (i = 0; i < GEM_NRXDESC; i++) {
811 		rxs = &sc->sc_rxsoft[i];
812 		if (rxs->rxs_mbuf == NULL) {
813 			if ((error = gem_add_rxbuf(sc, i)) != 0) {
814 				device_printf(sc->sc_dev,
815 				    "unable to allocate or map RX buffer %d, "
816 				    "error = %d\n", i, error);
817 				/*
818 				 * XXX we should attempt to run with fewer
819 				 * receive buffers instead of just failing.
820 				 */
821 				gem_rxdrain(sc);
822 				return (1);
823 			}
824 		} else
825 			GEM_INIT_RXDESC(sc, i);
826 	}
827 	sc->sc_rxptr = 0;
828 	GEM_CDSYNC(sc, BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD);
829 
830 	return (0);
831 }
832 
833 static u_int
834 gem_ringsize(u_int sz)
835 {
836 
837 	switch (sz) {
838 	case 32:
839 		return (GEM_RING_SZ_32);
840 	case 64:
841 		return (GEM_RING_SZ_64);
842 	case 128:
843 		return (GEM_RING_SZ_128);
844 	case 256:
845 		return (GEM_RING_SZ_256);
846 	case 512:
847 		return (GEM_RING_SZ_512);
848 	case 1024:
849 		return (GEM_RING_SZ_1024);
850 	case 2048:
851 		return (GEM_RING_SZ_2048);
852 	case 4096:
853 		return (GEM_RING_SZ_4096);
854 	case 8192:
855 		return (GEM_RING_SZ_8192);
856 	default:
857 		printf("%s: invalid ring size %d\n", __func__, sz);
858 		return (GEM_RING_SZ_32);
859 	}
860 }
861 
862 static void
863 gem_init(void *xsc)
864 {
865 	struct gem_softc *sc = xsc;
866 
867 	GEM_LOCK(sc);
868 	gem_init_locked(sc);
869 	GEM_UNLOCK(sc);
870 }
871 
872 /*
873  * Initialization of interface; set up initialization block
874  * and transmit/receive descriptor rings.
875  */
876 static void
877 gem_init_locked(struct gem_softc *sc)
878 {
879 	struct ifnet *ifp = sc->sc_ifp;
880 	uint32_t v;
881 
882 	GEM_LOCK_ASSERT(sc, MA_OWNED);
883 
884 #ifdef GEM_DEBUG
885 	CTR2(KTR_GEM, "%s: %s: calling stop", device_get_name(sc->sc_dev),
886 	    __func__);
887 #endif
888 	/*
889 	 * Initialization sequence.  The numbered steps below correspond
890 	 * to the sequence outlined in section 6.3.5.1 in the Ethernet
891 	 * Channel Engine manual (part of the PCIO manual).
892 	 * See also the STP2002-STQ document from Sun Microsystems.
893 	 */
894 
895 	/* step 1 & 2.  Reset the Ethernet Channel. */
896 	gem_stop(ifp, 0);
897 	gem_reset(sc);
898 #ifdef GEM_DEBUG
899 	CTR2(KTR_GEM, "%s: %s: restarting", device_get_name(sc->sc_dev),
900 	    __func__);
901 #endif
902 
903 	/* Re-initialize the MIF. */
904 	gem_mifinit(sc);
905 
906 	/* step 3.  Setup data structures in host memory. */
907 	if (gem_meminit(sc) != 0)
908 		return;
909 
910 	/* step 4.  TX MAC registers & counters */
911 	gem_init_regs(sc);
912 
913 	/* step 5.  RX MAC registers & counters */
914 	gem_setladrf(sc);
915 
916 	/* step 6 & 7.  Program Descriptor Ring Base Addresses. */
917 	/* NOTE: we use only 32-bit DMA addresses here. */
918 	GEM_BANK1_WRITE_4(sc, GEM_TX_RING_PTR_HI, 0);
919 	GEM_BANK1_WRITE_4(sc, GEM_TX_RING_PTR_LO, GEM_CDTXADDR(sc, 0));
920 
921 	GEM_BANK1_WRITE_4(sc, GEM_RX_RING_PTR_HI, 0);
922 	GEM_BANK1_WRITE_4(sc, GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
923 #ifdef GEM_DEBUG
924 	CTR3(KTR_GEM, "loading RX ring %lx, TX ring %lx, cddma %lx",
925 	    GEM_CDRXADDR(sc, 0), GEM_CDTXADDR(sc, 0), sc->sc_cddma);
926 #endif
927 
928 	/* step 8.  Global Configuration & Interrupt Mask */
929 	GEM_BANK1_WRITE_4(sc, GEM_INTMASK,
930 	    ~(GEM_INTR_TX_INTME | GEM_INTR_TX_EMPTY | GEM_INTR_RX_DONE |
931 	    GEM_INTR_RX_NOBUF | GEM_INTR_RX_TAG_ERR | GEM_INTR_PERR |
932 	    GEM_INTR_BERR
933 #ifdef GEM_DEBUG
934 	    | GEM_INTR_PCS | GEM_INTR_MIF
935 #endif
936 	    ));
937 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_MASK,
938 	    GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT);
939 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_MASK,
940 	    GEM_MAC_TX_XMIT_DONE | GEM_MAC_TX_DEFER_EXP);
941 #ifdef GEM_DEBUG
942 	GEM_BANK1_WRITE_4(sc, GEM_MAC_CONTROL_MASK,
943 	    ~(GEM_MAC_PAUSED | GEM_MAC_PAUSE | GEM_MAC_RESUME));
944 #else
945 	GEM_BANK1_WRITE_4(sc, GEM_MAC_CONTROL_MASK,
946 	    GEM_MAC_PAUSED | GEM_MAC_PAUSE | GEM_MAC_RESUME);
947 #endif
948 
949 	/* step 9.  ETX Configuration: use mostly default values. */
950 
951 	/* Enable DMA. */
952 	v = gem_ringsize(GEM_NTXDESC /* XXX */);
953 	v |= ((sc->sc_variant == GEM_SUN_ERI ? 0x100 : 0x4ff) << 10) &
954 	    GEM_TX_CONFIG_TXFIFO_TH;
955 	GEM_BANK1_WRITE_4(sc, GEM_TX_CONFIG, v | GEM_TX_CONFIG_TXDMA_EN);
956 
957 	/* step 10.  ERX Configuration */
958 
959 	/* Encode Receive Descriptor ring size. */
960 	v = gem_ringsize(GEM_NRXDESC /* XXX */);
961 	/* RX TCP/UDP checksum offset */
962 	v |= ((ETHER_HDR_LEN + sizeof(struct ip)) <<
963 	    GEM_RX_CONFIG_CXM_START_SHFT);
964 
965 	/* Enable DMA. */
966 	GEM_BANK1_WRITE_4(sc, GEM_RX_CONFIG,
967 	    v | (GEM_THRSH_1024 << GEM_RX_CONFIG_FIFO_THRS_SHIFT) |
968 	    (2 << GEM_RX_CONFIG_FBOFF_SHFT) | GEM_RX_CONFIG_RXDMA_EN);
969 
970 	GEM_BANK1_WRITE_4(sc, GEM_RX_BLANKING,
971 	    (6 << GEM_RX_BLANKING_TIME_SHIFT) | 6);
972 
973 	/*
974 	 * The following value is for an OFF Threshold of about 3/4 full
975 	 * and an ON Threshold of 1/4 full.
976 	 */
977 	GEM_BANK1_WRITE_4(sc, GEM_RX_PAUSE_THRESH,
978 	    (3 * sc->sc_rxfifosize / 256) |
979 	    ((sc->sc_rxfifosize / 256) << 12));
980 
981 	/* step 11.  Configure Media. */
982 
983 	/* step 12.  RX_MAC Configuration Register */
984 	v = GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG);
985 	v |= GEM_MAC_RX_ENABLE | GEM_MAC_RX_STRIP_CRC;
986 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, 0);
987 	GEM_BANK1_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
988 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
989 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0))
990 		device_printf(sc->sc_dev, "cannot configure RX MAC\n");
991 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, v);
992 
993 	/* step 13. TX_MAC Configuration Register */
994 	v = GEM_BANK1_READ_4(sc, GEM_MAC_TX_CONFIG);
995 	v |= GEM_MAC_TX_ENABLE;
996 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG, 0);
997 	GEM_BANK1_BARRIER(sc, GEM_MAC_TX_CONFIG, 4,
998 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
999 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0))
1000 		device_printf(sc->sc_dev, "cannot configure TX MAC\n");
1001 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG, v);
1002 
1003 	/* step 14.  Issue Transmit Pending command. */
1004 
1005 	/* step 15.  Give the reciever a swift kick. */
1006 	GEM_BANK1_WRITE_4(sc, GEM_RX_KICK, GEM_NRXDESC - 4);
1007 
1008 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
1009 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1010 
1011 	mii_mediachg(sc->sc_mii);
1012 
1013 	/* Start the one second timer. */
1014 	sc->sc_wdog_timer = 0;
1015 	callout_reset(&sc->sc_tick_ch, hz, gem_tick, sc);
1016 }
1017 
1018 static int
1019 gem_load_txmbuf(struct gem_softc *sc, struct mbuf **m_head)
1020 {
1021 	bus_dma_segment_t txsegs[GEM_NTXSEGS];
1022 	struct gem_txsoft *txs;
1023 	struct ip *ip;
1024 	struct mbuf *m;
1025 	uint64_t cflags, flags;
1026 	int error, nexttx, nsegs, offset, seg;
1027 
1028 	/* Get a work queue entry. */
1029 	if ((txs = STAILQ_FIRST(&sc->sc_txfreeq)) == NULL) {
1030 		/* Ran out of descriptors. */
1031 		return (ENOBUFS);
1032 	}
1033 
1034 	cflags = 0;
1035 	if (((*m_head)->m_pkthdr.csum_flags & sc->sc_csum_features) != 0) {
1036 		if (M_WRITABLE(*m_head) == 0) {
1037 			m = m_dup(*m_head, M_DONTWAIT);
1038 			m_freem(*m_head);
1039 			*m_head = m;
1040 			if (m == NULL)
1041 				return (ENOBUFS);
1042 		}
1043 		offset = sizeof(struct ether_header);
1044 		m = m_pullup(*m_head, offset + sizeof(struct ip));
1045 		if (m == NULL) {
1046 			*m_head = NULL;
1047 			return (ENOBUFS);
1048 		}
1049 		ip = (struct ip *)(mtod(m, caddr_t) + offset);
1050 		offset += (ip->ip_hl << 2);
1051 		cflags = offset << GEM_TD_CXSUM_STARTSHFT |
1052 		    ((offset + m->m_pkthdr.csum_data) <<
1053 		    GEM_TD_CXSUM_STUFFSHFT) | GEM_TD_CXSUM_ENABLE;
1054 		*m_head = m;
1055 	}
1056 
1057 	error = bus_dmamap_load_mbuf_sg(sc->sc_tdmatag, txs->txs_dmamap,
1058 	    *m_head, txsegs, &nsegs, BUS_DMA_NOWAIT);
1059 	if (error == EFBIG) {
1060 		m = m_collapse(*m_head, M_DONTWAIT, GEM_NTXSEGS);
1061 		if (m == NULL) {
1062 			m_freem(*m_head);
1063 			*m_head = NULL;
1064 			return (ENOBUFS);
1065 		}
1066 		*m_head = m;
1067 		error = bus_dmamap_load_mbuf_sg(sc->sc_tdmatag,
1068 		    txs->txs_dmamap, *m_head, txsegs, &nsegs,
1069 		    BUS_DMA_NOWAIT);
1070 		if (error != 0) {
1071 			m_freem(*m_head);
1072 			*m_head = NULL;
1073 			return (error);
1074 		}
1075 	} else if (error != 0)
1076 		return (error);
1077 	/* If nsegs is wrong then the stack is corrupt. */
1078 	KASSERT(nsegs <= GEM_NTXSEGS,
1079 	    ("%s: too many DMA segments (%d)", __func__, nsegs));
1080 	if (nsegs == 0) {
1081 		m_freem(*m_head);
1082 		*m_head = NULL;
1083 		return (EIO);
1084 	}
1085 
1086 	/*
1087 	 * Ensure we have enough descriptors free to describe
1088 	 * the packet.  Note, we always reserve one descriptor
1089 	 * at the end of the ring as a termination point, in
1090 	 * order to prevent wrap-around.
1091 	 */
1092 	if (nsegs > sc->sc_txfree - 1) {
1093 		txs->txs_ndescs = 0;
1094 		bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
1095 		return (ENOBUFS);
1096 	}
1097 
1098 	txs->txs_ndescs = nsegs;
1099 	txs->txs_firstdesc = sc->sc_txnext;
1100 	nexttx = txs->txs_firstdesc;
1101 	for (seg = 0; seg < nsegs; seg++, nexttx = GEM_NEXTTX(nexttx)) {
1102 #ifdef GEM_DEBUG
1103 		CTR6(KTR_GEM,
1104 		    "%s: mapping seg %d (txd %d), len %lx, addr %#lx (%#lx)",
1105 		    __func__, seg, nexttx, txsegs[seg].ds_len,
1106 		    txsegs[seg].ds_addr,
1107 		    GEM_DMA_WRITE(sc, txsegs[seg].ds_addr));
1108 #endif
1109 		sc->sc_txdescs[nexttx].gd_addr =
1110 		    GEM_DMA_WRITE(sc, txsegs[seg].ds_addr);
1111 		KASSERT(txsegs[seg].ds_len < GEM_TD_BUFSIZE,
1112 		    ("%s: segment size too large!", __func__));
1113 		flags = txsegs[seg].ds_len & GEM_TD_BUFSIZE;
1114 		sc->sc_txdescs[nexttx].gd_flags =
1115 		    GEM_DMA_WRITE(sc, flags | cflags);
1116 		txs->txs_lastdesc = nexttx;
1117 	}
1118 
1119 	/* Set EOP on the last descriptor. */
1120 #ifdef GEM_DEBUG
1121 	CTR3(KTR_GEM, "%s: end of packet at segment %d, TX %d",
1122 	    __func__, seg, nexttx);
1123 #endif
1124 	sc->sc_txdescs[txs->txs_lastdesc].gd_flags |=
1125 	    GEM_DMA_WRITE(sc, GEM_TD_END_OF_PACKET);
1126 
1127 	/* Lastly set SOP on the first descriptor. */
1128 #ifdef GEM_DEBUG
1129 	CTR3(KTR_GEM, "%s: start of packet at segment %d, TX %d",
1130 	    __func__, seg, nexttx);
1131 #endif
1132 	if (++sc->sc_txwin > GEM_NTXSEGS * 2 / 3) {
1133 		sc->sc_txwin = 0;
1134 		flags |= GEM_TD_INTERRUPT_ME;
1135 		sc->sc_txdescs[txs->txs_firstdesc].gd_flags |=
1136 		    GEM_DMA_WRITE(sc, GEM_TD_INTERRUPT_ME |
1137 		    GEM_TD_START_OF_PACKET);
1138 	} else
1139 		sc->sc_txdescs[txs->txs_firstdesc].gd_flags |=
1140 		    GEM_DMA_WRITE(sc, GEM_TD_START_OF_PACKET);
1141 
1142 	/* Sync the DMA map. */
1143 	bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
1144 	    BUS_DMASYNC_PREWRITE);
1145 
1146 #ifdef GEM_DEBUG
1147 	CTR4(KTR_GEM, "%s: setting firstdesc=%d, lastdesc=%d, ndescs=%d",
1148 	    __func__, txs->txs_firstdesc, txs->txs_lastdesc,
1149 	    txs->txs_ndescs);
1150 #endif
1151 	STAILQ_REMOVE_HEAD(&sc->sc_txfreeq, txs_q);
1152 	STAILQ_INSERT_TAIL(&sc->sc_txdirtyq, txs, txs_q);
1153 	txs->txs_mbuf = *m_head;
1154 
1155 	sc->sc_txnext = GEM_NEXTTX(txs->txs_lastdesc);
1156 	sc->sc_txfree -= txs->txs_ndescs;
1157 
1158 	return (0);
1159 }
1160 
1161 static void
1162 gem_init_regs(struct gem_softc *sc)
1163 {
1164 	const u_char *laddr = IF_LLADDR(sc->sc_ifp);
1165 
1166 	/* These registers are not cleared on reset. */
1167 	if ((sc->sc_flags & GEM_INITED) == 0) {
1168 		/* magic values */
1169 		GEM_BANK1_WRITE_4(sc, GEM_MAC_IPG0, 0);
1170 		GEM_BANK1_WRITE_4(sc, GEM_MAC_IPG1, 8);
1171 		GEM_BANK1_WRITE_4(sc, GEM_MAC_IPG2, 4);
1172 
1173 		GEM_BANK1_WRITE_4(sc, GEM_MAC_MAC_MIN_FRAME, ETHER_MIN_LEN);
1174 		/* max frame and max burst size */
1175 		GEM_BANK1_WRITE_4(sc, GEM_MAC_MAC_MAX_FRAME,
1176 		    (ETHER_MAX_LEN + ETHER_VLAN_ENCAP_LEN) | (0x2000 << 16));
1177 
1178 		GEM_BANK1_WRITE_4(sc, GEM_MAC_PREAMBLE_LEN, 0x7);
1179 		GEM_BANK1_WRITE_4(sc, GEM_MAC_JAM_SIZE, 0x4);
1180 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ATTEMPT_LIMIT, 0x10);
1181 		/* dunno... */
1182 		GEM_BANK1_WRITE_4(sc, GEM_MAC_CONTROL_TYPE, 0x8088);
1183 		GEM_BANK1_WRITE_4(sc, GEM_MAC_RANDOM_SEED,
1184 		    ((laddr[5] << 8) | laddr[4]) & 0x3ff);
1185 
1186 		/* secondary MAC address: 0:0:0:0:0:0 */
1187 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR3, 0);
1188 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR4, 0);
1189 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR5, 0);
1190 
1191 		/* MAC control address: 01:80:c2:00:00:01 */
1192 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR6, 0x0001);
1193 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR7, 0xc200);
1194 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR8, 0x0180);
1195 
1196 		/* MAC filter address: 0:0:0:0:0:0 */
1197 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR_FILTER0, 0);
1198 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR_FILTER1, 0);
1199 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR_FILTER2, 0);
1200 
1201 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADR_FLT_MASK1_2, 0);
1202 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADR_FLT_MASK0, 0);
1203 
1204 		sc->sc_flags |= GEM_INITED;
1205 	}
1206 
1207 	/* Counters need to be zeroed. */
1208 	GEM_BANK1_WRITE_4(sc, GEM_MAC_NORM_COLL_CNT, 0);
1209 	GEM_BANK1_WRITE_4(sc, GEM_MAC_FIRST_COLL_CNT, 0);
1210 	GEM_BANK1_WRITE_4(sc, GEM_MAC_EXCESS_COLL_CNT, 0);
1211 	GEM_BANK1_WRITE_4(sc, GEM_MAC_LATE_COLL_CNT, 0);
1212 	GEM_BANK1_WRITE_4(sc, GEM_MAC_DEFER_TMR_CNT, 0);
1213 	GEM_BANK1_WRITE_4(sc, GEM_MAC_PEAK_ATTEMPTS, 0);
1214 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_FRAME_COUNT, 0);
1215 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_LEN_ERR_CNT, 0);
1216 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_ALIGN_ERR, 0);
1217 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CRC_ERR_CNT, 0);
1218 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CODE_VIOL, 0);
1219 
1220 	/* Set XOFF PAUSE time. */
1221 	GEM_BANK1_WRITE_4(sc, GEM_MAC_SEND_PAUSE_CMD, 0x1BF0);
1222 
1223 	/*
1224 	 * Set the internal arbitration to "infinite" bursts of the
1225 	 * maximum length of 31 * 64 bytes so DMA transfers aren't
1226 	 * split up in cache line size chunks.  This greatly improves
1227 	 * especially RX performance.
1228 	 * Enable silicon bug workarounds for the Apple variants.
1229 	 */
1230 	GEM_BANK1_WRITE_4(sc, GEM_CONFIG,
1231 	    GEM_CONFIG_TXDMA_LIMIT | GEM_CONFIG_RXDMA_LIMIT |
1232 	    GEM_CONFIG_BURST_INF | (GEM_IS_APPLE(sc) ?
1233 	    GEM_CONFIG_RONPAULBIT | GEM_CONFIG_BUG2FIX : 0));
1234 
1235 	/* Set the station address. */
1236 	GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR0, (laddr[4] << 8) | laddr[5]);
1237 	GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR1, (laddr[2] << 8) | laddr[3]);
1238 	GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR2, (laddr[0] << 8) | laddr[1]);
1239 
1240 	/* Enable MII outputs. */
1241 	GEM_BANK1_WRITE_4(sc, GEM_MAC_XIF_CONFIG, GEM_MAC_XIF_TX_MII_ENA);
1242 }
1243 
1244 static void
1245 gem_start(struct ifnet *ifp)
1246 {
1247 	struct gem_softc *sc = ifp->if_softc;
1248 
1249 	GEM_LOCK(sc);
1250 	gem_start_locked(ifp);
1251 	GEM_UNLOCK(sc);
1252 }
1253 
1254 static void
1255 gem_start_locked(struct ifnet *ifp)
1256 {
1257 	struct gem_softc *sc = ifp->if_softc;
1258 	struct mbuf *m;
1259 	int ntx;
1260 
1261 	if ((ifp->if_drv_flags & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
1262 	    IFF_DRV_RUNNING || (sc->sc_flags & GEM_LINK) == 0)
1263 		return;
1264 
1265 #ifdef GEM_DEBUG
1266 	CTR4(KTR_GEM, "%s: %s: txfree %d, txnext %d",
1267 	    device_get_name(sc->sc_dev), __func__, sc->sc_txfree,
1268 	    sc->sc_txnext);
1269 #endif
1270 	ntx = 0;
1271 	for (; !IFQ_DRV_IS_EMPTY(&ifp->if_snd) && sc->sc_txfree > 1;) {
1272 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
1273 		if (m == NULL)
1274 			break;
1275 		if (gem_load_txmbuf(sc, &m) != 0) {
1276 			if (m == NULL)
1277 				break;
1278 			ifp->if_drv_flags |= IFF_DRV_OACTIVE;
1279 			IFQ_DRV_PREPEND(&ifp->if_snd, m);
1280 			break;
1281 		}
1282 		ntx++;
1283 		/* Kick the transmitter. */
1284 #ifdef GEM_DEBUG
1285 		CTR3(KTR_GEM, "%s: %s: kicking TX %d",
1286 		    device_get_name(sc->sc_dev), __func__, sc->sc_txnext);
1287 #endif
1288 		GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
1289 		GEM_BANK1_WRITE_4(sc, GEM_TX_KICK, sc->sc_txnext);
1290 
1291 		BPF_MTAP(ifp, m);
1292 	}
1293 
1294 	if (ntx > 0) {
1295 #ifdef GEM_DEBUG
1296 		CTR2(KTR_GEM, "%s: packets enqueued, OWN on %d",
1297 		    device_get_name(sc->sc_dev), sc->sc_txnext);
1298 #endif
1299 
1300 		/* Set a watchdog timer in case the chip flakes out. */
1301 		sc->sc_wdog_timer = 5;
1302 #ifdef GEM_DEBUG
1303 		CTR3(KTR_GEM, "%s: %s: watchdog %d",
1304 		    device_get_name(sc->sc_dev), __func__,
1305 		    sc->sc_wdog_timer);
1306 #endif
1307 	}
1308 }
1309 
1310 static void
1311 gem_tint(struct gem_softc *sc)
1312 {
1313 	struct ifnet *ifp = sc->sc_ifp;
1314 	struct gem_txsoft *txs;
1315 	int txlast, progress;
1316 #ifdef GEM_DEBUG
1317 	int i;
1318 
1319 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
1320 #endif
1321 
1322 	/*
1323 	 * Go through our TX list and free mbufs for those
1324 	 * frames that have been transmitted.
1325 	 */
1326 	progress = 0;
1327 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD);
1328 	while ((txs = STAILQ_FIRST(&sc->sc_txdirtyq)) != NULL) {
1329 
1330 #ifdef GEM_DEBUG
1331 		if ((ifp->if_flags & IFF_DEBUG) != 0) {
1332 			printf("    txsoft %p transmit chain:\n", txs);
1333 			for (i = txs->txs_firstdesc;; i = GEM_NEXTTX(i)) {
1334 				printf("descriptor %d: ", i);
1335 				printf("gd_flags: 0x%016llx\t",
1336 				    (long long)GEM_DMA_READ(sc,
1337 				    sc->sc_txdescs[i].gd_flags));
1338 				printf("gd_addr: 0x%016llx\n",
1339 				    (long long)GEM_DMA_READ(sc,
1340 				    sc->sc_txdescs[i].gd_addr));
1341 				if (i == txs->txs_lastdesc)
1342 					break;
1343 			}
1344 		}
1345 #endif
1346 
1347 		/*
1348 		 * In theory, we could harvest some descriptors before
1349 		 * the ring is empty, but that's a bit complicated.
1350 		 *
1351 		 * GEM_TX_COMPLETION points to the last descriptor
1352 		 * processed + 1.
1353 		 */
1354 		txlast = GEM_BANK1_READ_4(sc, GEM_TX_COMPLETION);
1355 #ifdef GEM_DEBUG
1356 		CTR4(KTR_GEM, "%s: txs->txs_firstdesc = %d, "
1357 		    "txs->txs_lastdesc = %d, txlast = %d",
1358 		    __func__, txs->txs_firstdesc, txs->txs_lastdesc, txlast);
1359 #endif
1360 		if (txs->txs_firstdesc <= txs->txs_lastdesc) {
1361 			if ((txlast >= txs->txs_firstdesc) &&
1362 			    (txlast <= txs->txs_lastdesc))
1363 				break;
1364 		} else {
1365 			/* Ick -- this command wraps. */
1366 			if ((txlast >= txs->txs_firstdesc) ||
1367 			    (txlast <= txs->txs_lastdesc))
1368 				break;
1369 		}
1370 
1371 #ifdef GEM_DEBUG
1372 		CTR1(KTR_GEM, "%s: releasing a descriptor", __func__);
1373 #endif
1374 		STAILQ_REMOVE_HEAD(&sc->sc_txdirtyq, txs_q);
1375 
1376 		sc->sc_txfree += txs->txs_ndescs;
1377 
1378 		bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
1379 		    BUS_DMASYNC_POSTWRITE);
1380 		bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
1381 		if (txs->txs_mbuf != NULL) {
1382 			m_freem(txs->txs_mbuf);
1383 			txs->txs_mbuf = NULL;
1384 		}
1385 
1386 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
1387 
1388 		ifp->if_opackets++;
1389 		progress = 1;
1390 	}
1391 
1392 #ifdef GEM_DEBUG
1393 	CTR4(KTR_GEM, "%s: GEM_TX_STATE_MACHINE %x GEM_TX_DATA_PTR %llx "
1394 	    "GEM_TX_COMPLETION %x",
1395 	    __func__, GEM_BANK1_READ_4(sc, GEM_TX_STATE_MACHINE),
1396 	    ((long long)GEM_BANK1_READ_4(sc, GEM_TX_DATA_PTR_HI) << 32) |
1397 	    GEM_BANK1_READ_4(sc, GEM_TX_DATA_PTR_LO),
1398 	    GEM_BANK1_READ_4(sc, GEM_TX_COMPLETION));
1399 #endif
1400 
1401 	if (progress) {
1402 		if (sc->sc_txfree == GEM_NTXDESC - 1)
1403 			sc->sc_txwin = 0;
1404 
1405 		/*
1406 		 * We freed some descriptors, so reset IFF_DRV_OACTIVE
1407 		 * and restart.
1408 		 */
1409 		ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1410 		sc->sc_wdog_timer = STAILQ_EMPTY(&sc->sc_txdirtyq) ? 0 : 5;
1411 
1412 		gem_start_locked(ifp);
1413 	}
1414 
1415 #ifdef GEM_DEBUG
1416 	CTR3(KTR_GEM, "%s: %s: watchdog %d",
1417 	    device_get_name(sc->sc_dev), __func__, sc->sc_wdog_timer);
1418 #endif
1419 }
1420 
1421 #ifdef GEM_RINT_TIMEOUT
1422 static void
1423 gem_rint_timeout(void *arg)
1424 {
1425 	struct gem_softc *sc = arg;
1426 
1427 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1428 	gem_rint(sc);
1429 }
1430 #endif
1431 
1432 static void
1433 gem_rint(struct gem_softc *sc)
1434 {
1435 	struct ifnet *ifp = sc->sc_ifp;
1436 	struct mbuf *m;
1437 	uint64_t rxstat;
1438 	uint32_t rxcomp;
1439 
1440 #ifdef GEM_RINT_TIMEOUT
1441 	callout_stop(&sc->sc_rx_ch);
1442 #endif
1443 #ifdef GEM_DEBUG
1444 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
1445 #endif
1446 
1447 	/*
1448 	 * Read the completion register once.  This limits
1449 	 * how long the following loop can execute.
1450 	 */
1451 	rxcomp = GEM_BANK1_READ_4(sc, GEM_RX_COMPLETION);
1452 
1453 #ifdef GEM_DEBUG
1454 	CTR3(KTR_GEM, "%s: sc->rxptr %d, complete %d",
1455 	    __func__, sc->sc_rxptr, rxcomp);
1456 #endif
1457 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD);
1458 	for (; sc->sc_rxptr != rxcomp;) {
1459 		m = sc->sc_rxsoft[sc->sc_rxptr].rxs_mbuf;
1460 		rxstat = GEM_DMA_READ(sc,
1461 		    sc->sc_rxdescs[sc->sc_rxptr].gd_flags);
1462 
1463 		if (rxstat & GEM_RD_OWN) {
1464 #ifdef GEM_RINT_TIMEOUT
1465 			/*
1466 			 * The descriptor is still marked as owned, although
1467 			 * it is supposed to have completed.  This has been
1468 			 * observed on some machines.  Just exiting here
1469 			 * might leave the packet sitting around until another
1470 			 * one arrives to trigger a new interrupt, which is
1471 			 * generally undesirable, so set up a timeout.
1472 			 */
1473 			callout_reset(&sc->sc_rx_ch, GEM_RXOWN_TICKS,
1474 			    gem_rint_timeout, sc);
1475 #endif
1476 			m = NULL;
1477 			goto kickit;
1478 		}
1479 
1480 		if (rxstat & GEM_RD_BAD_CRC) {
1481 			ifp->if_ierrors++;
1482 			device_printf(sc->sc_dev, "receive error: CRC error\n");
1483 			GEM_INIT_RXDESC(sc, sc->sc_rxptr);
1484 			m = NULL;
1485 			goto kickit;
1486 		}
1487 
1488 #ifdef GEM_DEBUG
1489 		if ((ifp->if_flags & IFF_DEBUG) != 0) {
1490 			printf("    rxsoft %p descriptor %d: ",
1491 			    &sc->sc_rxsoft[sc->sc_rxptr], sc->sc_rxptr);
1492 			printf("gd_flags: 0x%016llx\t",
1493 			    (long long)GEM_DMA_READ(sc,
1494 			    sc->sc_rxdescs[sc->sc_rxptr].gd_flags));
1495 			printf("gd_addr: 0x%016llx\n",
1496 			    (long long)GEM_DMA_READ(sc,
1497 			    sc->sc_rxdescs[sc->sc_rxptr].gd_addr));
1498 		}
1499 #endif
1500 
1501 		/*
1502 		 * Allocate a new mbuf cluster.  If that fails, we are
1503 		 * out of memory, and must drop the packet and recycle
1504 		 * the buffer that's already attached to this descriptor.
1505 		 */
1506 		if (gem_add_rxbuf(sc, sc->sc_rxptr) != 0) {
1507 			ifp->if_ierrors++;
1508 			GEM_INIT_RXDESC(sc, sc->sc_rxptr);
1509 			m = NULL;
1510 		}
1511 
1512  kickit:
1513 		/*
1514 		 * Update the RX kick register.  This register has to point
1515 		 * to the descriptor after the last valid one (before the
1516 		 * current batch) and must be incremented in multiples of
1517 		 * 4 (because the DMA engine fetches/updates descriptors
1518 		 * in batches of 4).
1519 		 */
1520 		sc->sc_rxptr = GEM_NEXTRX(sc->sc_rxptr);
1521 		if ((sc->sc_rxptr % 4) == 0) {
1522 			GEM_CDSYNC(sc,
1523 			    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
1524 			GEM_BANK1_WRITE_4(sc, GEM_RX_KICK,
1525 			    (sc->sc_rxptr + GEM_NRXDESC - 4) &
1526 			    GEM_NRXDESC_MASK);
1527 		}
1528 
1529 		if (m == NULL) {
1530 			if (rxstat & GEM_RD_OWN)
1531 				break;
1532 			continue;
1533 		}
1534 
1535 		ifp->if_ipackets++;
1536 		m->m_data += 2; /* We're already off by two */
1537 		m->m_pkthdr.rcvif = ifp;
1538 		m->m_pkthdr.len = m->m_len = GEM_RD_BUFLEN(rxstat);
1539 
1540 		if ((ifp->if_capenable & IFCAP_RXCSUM) != 0)
1541 			gem_rxcksum(m, rxstat);
1542 
1543 		/* Pass it on. */
1544 		GEM_UNLOCK(sc);
1545 		(*ifp->if_input)(ifp, m);
1546 		GEM_LOCK(sc);
1547 	}
1548 
1549 #ifdef GEM_DEBUG
1550 	CTR3(KTR_GEM, "%s: done sc->rxptr %d, complete %d", __func__,
1551 	    sc->sc_rxptr, GEM_BANK1_READ_4(sc, GEM_RX_COMPLETION));
1552 #endif
1553 }
1554 
1555 static int
1556 gem_add_rxbuf(struct gem_softc *sc, int idx)
1557 {
1558 	struct gem_rxsoft *rxs = &sc->sc_rxsoft[idx];
1559 	struct mbuf *m;
1560 	bus_dma_segment_t segs[1];
1561 	int error, nsegs;
1562 
1563 	m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
1564 	if (m == NULL)
1565 		return (ENOBUFS);
1566 	m->m_len = m->m_pkthdr.len = m->m_ext.ext_size;
1567 
1568 #ifdef GEM_DEBUG
1569 	/* Bzero the packet to check DMA. */
1570 	memset(m->m_ext.ext_buf, 0, m->m_ext.ext_size);
1571 #endif
1572 
1573 	if (rxs->rxs_mbuf != NULL) {
1574 		bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
1575 		    BUS_DMASYNC_POSTREAD);
1576 		bus_dmamap_unload(sc->sc_rdmatag, rxs->rxs_dmamap);
1577 	}
1578 
1579 	error = bus_dmamap_load_mbuf_sg(sc->sc_rdmatag, rxs->rxs_dmamap,
1580 	    m, segs, &nsegs, BUS_DMA_NOWAIT);
1581 	if (error != 0) {
1582 		device_printf(sc->sc_dev,
1583 		    "cannot load RS DMA map %d, error = %d\n", idx, error);
1584 		m_freem(m);
1585 		return (error);
1586 	}
1587 	/* If nsegs is wrong then the stack is corrupt. */
1588 	KASSERT(nsegs == 1,
1589 	    ("%s: too many DMA segments (%d)", __func__, nsegs));
1590 	rxs->rxs_mbuf = m;
1591 	rxs->rxs_paddr = segs[0].ds_addr;
1592 
1593 	bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
1594 	    BUS_DMASYNC_PREREAD);
1595 
1596 	GEM_INIT_RXDESC(sc, idx);
1597 
1598 	return (0);
1599 }
1600 
1601 static void
1602 gem_eint(struct gem_softc *sc, u_int status)
1603 {
1604 
1605 	sc->sc_ifp->if_ierrors++;
1606 	if ((status & GEM_INTR_RX_TAG_ERR) != 0) {
1607 		gem_reset_rxdma(sc);
1608 		return;
1609 	}
1610 
1611 	device_printf(sc->sc_dev, "%s: status=%x\n", __func__, status);
1612 }
1613 
1614 void
1615 gem_intr(void *v)
1616 {
1617 	struct gem_softc *sc = v;
1618 	uint32_t status, status2;
1619 
1620 	GEM_LOCK(sc);
1621 	status = GEM_BANK1_READ_4(sc, GEM_STATUS);
1622 
1623 #ifdef GEM_DEBUG
1624 	CTR4(KTR_GEM, "%s: %s: cplt %x, status %x",
1625 	    device_get_name(sc->sc_dev), __func__, (status >> 19),
1626 	    (u_int)status);
1627 
1628 	/*
1629 	 * PCS interrupts must be cleared, otherwise no traffic is passed!
1630 	 */
1631 	if ((status & GEM_INTR_PCS) != 0) {
1632 		status2 =
1633 		    GEM_BANK1_READ_4(sc, GEM_MII_INTERRUP_STATUS) |
1634 		    GEM_BANK1_READ_4(sc, GEM_MII_INTERRUP_STATUS);
1635 		if ((status2 & GEM_MII_INTERRUP_LINK) != 0)
1636 			device_printf(sc->sc_dev,
1637 			    "%s: PCS link status changed\n", __func__);
1638 	}
1639 	if ((status & GEM_MAC_CONTROL_STATUS) != 0) {
1640 		status2 = GEM_BANK1_READ_4(sc, GEM_MAC_CONTROL_STATUS);
1641 		if ((status2 & GEM_MAC_PAUSED) != 0)
1642 			device_printf(sc->sc_dev,
1643 			    "%s: PAUSE received (PAUSE time %d slots)\n",
1644 			    __func__, GEM_MAC_PAUSE_TIME(status2));
1645 		if ((status2 & GEM_MAC_PAUSE) != 0)
1646 			device_printf(sc->sc_dev,
1647 			    "%s: transited to PAUSE state\n", __func__);
1648 		if ((status2 & GEM_MAC_RESUME) != 0)
1649 			device_printf(sc->sc_dev,
1650 			    "%s: transited to non-PAUSE state\n", __func__);
1651 	}
1652 	if ((status & GEM_INTR_MIF) != 0)
1653 		device_printf(sc->sc_dev, "%s: MIF interrupt\n", __func__);
1654 #endif
1655 
1656 	if ((status &
1657 	    (GEM_INTR_RX_TAG_ERR | GEM_INTR_PERR | GEM_INTR_BERR)) != 0)
1658 		gem_eint(sc, status);
1659 
1660 	if ((status & (GEM_INTR_RX_DONE | GEM_INTR_RX_NOBUF)) != 0)
1661 		gem_rint(sc);
1662 
1663 	if ((status & (GEM_INTR_TX_EMPTY | GEM_INTR_TX_INTME)) != 0)
1664 		gem_tint(sc);
1665 
1666 	if (status & GEM_INTR_TX_MAC) {
1667 		status2 = GEM_BANK1_READ_4(sc, GEM_MAC_TX_STATUS);
1668 		if ((status2 &
1669 		    ~(GEM_MAC_TX_XMIT_DONE | GEM_MAC_TX_DEFER_EXP)) != 0)
1670 			device_printf(sc->sc_dev,
1671 			    "MAC TX fault, status %x\n", status2);
1672 		if ((status2 &
1673 		    (GEM_MAC_TX_UNDERRUN | GEM_MAC_TX_PKT_TOO_LONG)) != 0)
1674 			gem_init_locked(sc);
1675 	}
1676 	if (status & GEM_INTR_RX_MAC) {
1677 		status2 = GEM_BANK1_READ_4(sc, GEM_MAC_RX_STATUS);
1678 		/*
1679 		 * At least with GEM_SUN_GEM and some GEM_SUN_ERI
1680 		 * revisions GEM_MAC_RX_OVERFLOW happen often due to a
1681 		 * silicon bug so handle them silently.  Moreover, it's
1682 		 * likely that the receiver has hung so we reset it.
1683 		 */
1684 		if ((status2 & GEM_MAC_RX_OVERFLOW) != 0) {
1685 			sc->sc_ifp->if_ierrors++;
1686 			gem_reset_rxdma(sc);
1687 		} else if ((status2 &
1688 		    ~(GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT)) != 0)
1689 			device_printf(sc->sc_dev,
1690 			    "MAC RX fault, status %x\n", status2);
1691 	}
1692 	GEM_UNLOCK(sc);
1693 }
1694 
1695 static int
1696 gem_watchdog(struct gem_softc *sc)
1697 {
1698 	struct ifnet *ifp = sc->sc_ifp;
1699 
1700 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1701 
1702 #ifdef GEM_DEBUG
1703 	CTR4(KTR_GEM,
1704 	    "%s: GEM_RX_CONFIG %x GEM_MAC_RX_STATUS %x GEM_MAC_RX_CONFIG %x",
1705 	    __func__, GEM_BANK1_READ_4(sc, GEM_RX_CONFIG),
1706 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_STATUS),
1707 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG));
1708 	CTR4(KTR_GEM,
1709 	    "%s: GEM_TX_CONFIG %x GEM_MAC_TX_STATUS %x GEM_MAC_TX_CONFIG %x",
1710 	    __func__, GEM_BANK1_READ_4(sc, GEM_TX_CONFIG),
1711 	    GEM_BANK1_READ_4(sc, GEM_MAC_TX_STATUS),
1712 	    GEM_BANK1_READ_4(sc, GEM_MAC_TX_CONFIG));
1713 #endif
1714 
1715 	if (sc->sc_wdog_timer == 0 || --sc->sc_wdog_timer != 0)
1716 		return (0);
1717 
1718 	if ((sc->sc_flags & GEM_LINK) != 0)
1719 		device_printf(sc->sc_dev, "device timeout\n");
1720 	else if (bootverbose)
1721 		device_printf(sc->sc_dev, "device timeout (no link)\n");
1722 	++ifp->if_oerrors;
1723 
1724 	/* Try to get more packets going. */
1725 	gem_init_locked(sc);
1726 	gem_start_locked(ifp);
1727 	return (EJUSTRETURN);
1728 }
1729 
1730 static void
1731 gem_mifinit(struct gem_softc *sc)
1732 {
1733 
1734 	/* Configure the MIF in frame mode. */
1735 	GEM_BANK1_WRITE_4(sc, GEM_MIF_CONFIG,
1736 	    GEM_BANK1_READ_4(sc, GEM_MIF_CONFIG) & ~GEM_MIF_CONFIG_BB_ENA);
1737 }
1738 
1739 /*
1740  * MII interface
1741  *
1742  * The GEM MII interface supports at least three different operating modes:
1743  *
1744  * Bitbang mode is implemented using data, clock and output enable registers.
1745  *
1746  * Frame mode is implemented by loading a complete frame into the frame
1747  * register and polling the valid bit for completion.
1748  *
1749  * Polling mode uses the frame register but completion is indicated by
1750  * an interrupt.
1751  *
1752  */
1753 int
1754 gem_mii_readreg(device_t dev, int phy, int reg)
1755 {
1756 	struct gem_softc *sc;
1757 	int n;
1758 	uint32_t v;
1759 
1760 #ifdef GEM_DEBUG_PHY
1761 	printf("%s: phy %d reg %d\n", __func__, phy, reg);
1762 #endif
1763 
1764 	sc = device_get_softc(dev);
1765 	if (sc->sc_phyad != -1 && phy != sc->sc_phyad)
1766 		return (0);
1767 
1768 	if ((sc->sc_flags & GEM_SERDES) != 0) {
1769 		switch (reg) {
1770 		case MII_BMCR:
1771 			reg = GEM_MII_CONTROL;
1772 			break;
1773 		case MII_BMSR:
1774 			reg = GEM_MII_STATUS;
1775 			break;
1776 		case MII_PHYIDR1:
1777 		case MII_PHYIDR2:
1778 			return (0);
1779 		case MII_ANAR:
1780 			reg = GEM_MII_ANAR;
1781 			break;
1782 		case MII_ANLPAR:
1783 			reg = GEM_MII_ANLPAR;
1784 			break;
1785 		case MII_EXTSR:
1786 			return (EXTSR_1000XFDX | EXTSR_1000XHDX);
1787 		default:
1788 			device_printf(sc->sc_dev,
1789 			    "%s: unhandled register %d\n", __func__, reg);
1790 			return (0);
1791 		}
1792 		return (GEM_BANK1_READ_4(sc, reg));
1793 	}
1794 
1795 	/* Construct the frame command. */
1796 	v = GEM_MIF_FRAME_READ |
1797 	    (phy << GEM_MIF_PHY_SHIFT) |
1798 	    (reg << GEM_MIF_REG_SHIFT);
1799 
1800 	GEM_BANK1_WRITE_4(sc, GEM_MIF_FRAME, v);
1801 	GEM_BANK1_BARRIER(sc, GEM_MIF_FRAME, 4,
1802 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1803 	for (n = 0; n < 100; n++) {
1804 		DELAY(1);
1805 		v = GEM_BANK1_READ_4(sc, GEM_MIF_FRAME);
1806 		if (v & GEM_MIF_FRAME_TA0)
1807 			return (v & GEM_MIF_FRAME_DATA);
1808 	}
1809 
1810 	device_printf(sc->sc_dev, "%s: timed out\n", __func__);
1811 	return (0);
1812 }
1813 
1814 int
1815 gem_mii_writereg(device_t dev, int phy, int reg, int val)
1816 {
1817 	struct gem_softc *sc;
1818 	int n;
1819 	uint32_t v;
1820 
1821 #ifdef GEM_DEBUG_PHY
1822 	printf("%s: phy %d reg %d val %x\n", phy, reg, val, __func__);
1823 #endif
1824 
1825 	sc = device_get_softc(dev);
1826 	if (sc->sc_phyad != -1 && phy != sc->sc_phyad)
1827 		return (0);
1828 
1829 	if ((sc->sc_flags & GEM_SERDES) != 0) {
1830 		switch (reg) {
1831 		case MII_BMSR:
1832 			reg = GEM_MII_STATUS;
1833 			break;
1834 		case MII_BMCR:
1835 			reg = GEM_MII_CONTROL;
1836 			if ((val & GEM_MII_CONTROL_RESET) == 0)
1837 				break;
1838 			GEM_BANK1_WRITE_4(sc, GEM_MII_CONTROL, val);
1839 			GEM_BANK1_BARRIER(sc, GEM_MII_CONTROL, 4,
1840 			    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1841 			if (!GEM_BANK1_BITWAIT(sc, GEM_MII_CONTROL,
1842 			    GEM_MII_CONTROL_RESET, 0))
1843 				device_printf(sc->sc_dev,
1844 				    "cannot reset PCS\n");
1845 			/* FALLTHROUGH */
1846 		case MII_ANAR:
1847 			GEM_BANK1_WRITE_4(sc, GEM_MII_CONFIG, 0);
1848 			GEM_BANK1_BARRIER(sc, GEM_MII_CONFIG, 4,
1849 			    BUS_SPACE_BARRIER_WRITE);
1850 			GEM_BANK1_WRITE_4(sc, GEM_MII_ANAR, val);
1851 			GEM_BANK1_WRITE_4(sc, GEM_MII_SLINK_CONTROL,
1852 			    GEM_MII_SLINK_LOOPBACK | GEM_MII_SLINK_EN_SYNC_D);
1853 			GEM_BANK1_WRITE_4(sc, GEM_MII_CONFIG,
1854 			    GEM_MII_CONFIG_ENABLE);
1855 			return (0);
1856 		case MII_ANLPAR:
1857 			reg = GEM_MII_ANLPAR;
1858 			break;
1859 		default:
1860 			device_printf(sc->sc_dev,
1861 			    "%s: unhandled register %d\n", __func__, reg);
1862 			return (0);
1863 		}
1864 		GEM_BANK1_WRITE_4(sc, reg, val);
1865 		return (0);
1866 	}
1867 
1868 	/* Construct the frame command. */
1869 	v = GEM_MIF_FRAME_WRITE |
1870 	    (phy << GEM_MIF_PHY_SHIFT) |
1871 	    (reg << GEM_MIF_REG_SHIFT) |
1872 	    (val & GEM_MIF_FRAME_DATA);
1873 
1874 	GEM_BANK1_WRITE_4(sc, GEM_MIF_FRAME, v);
1875 	GEM_BANK1_BARRIER(sc, GEM_MIF_FRAME, 4,
1876 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1877 	for (n = 0; n < 100; n++) {
1878 		DELAY(1);
1879 		v = GEM_BANK1_READ_4(sc, GEM_MIF_FRAME);
1880 		if (v & GEM_MIF_FRAME_TA0)
1881 			return (1);
1882 	}
1883 
1884 	device_printf(sc->sc_dev, "%s: timed out\n", __func__);
1885 	return (0);
1886 }
1887 
1888 void
1889 gem_mii_statchg(device_t dev)
1890 {
1891 	struct gem_softc *sc;
1892 	int gigabit;
1893 	uint32_t rxcfg, txcfg, v;
1894 
1895 	sc = device_get_softc(dev);
1896 
1897 #ifdef GEM_DEBUG
1898 	if ((sc->sc_ifp->if_flags & IFF_DEBUG) != 0)
1899 		device_printf(sc->sc_dev, "%s: status change: PHY = %d\n",
1900 		    __func__, sc->sc_phyad);
1901 #endif
1902 
1903 	if ((sc->sc_mii->mii_media_status & IFM_ACTIVE) != 0 &&
1904 	    IFM_SUBTYPE(sc->sc_mii->mii_media_active) != IFM_NONE)
1905 		sc->sc_flags |= GEM_LINK;
1906 	else
1907 		sc->sc_flags &= ~GEM_LINK;
1908 
1909 	switch (IFM_SUBTYPE(sc->sc_mii->mii_media_active)) {
1910 	case IFM_1000_SX:
1911 	case IFM_1000_LX:
1912 	case IFM_1000_CX:
1913 	case IFM_1000_T:
1914 		gigabit = 1;
1915 		break;
1916 	default:
1917 		gigabit = 0;
1918 	}
1919 
1920 	/*
1921 	 * The configuration done here corresponds to the steps F) and
1922 	 * G) and as far as enabling of RX and TX MAC goes also step H)
1923 	 * of the initialization sequence outlined in section 3.2.1 of
1924 	 * the GEM Gigabit Ethernet ASIC Specification.
1925 	 */
1926 
1927 	rxcfg = GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG);
1928 	rxcfg &= ~(GEM_MAC_RX_CARR_EXTEND | GEM_MAC_RX_ENABLE);
1929 	txcfg = GEM_MAC_TX_ENA_IPG0 | GEM_MAC_TX_NGU | GEM_MAC_TX_NGU_LIMIT;
1930 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) != 0)
1931 		txcfg |= GEM_MAC_TX_IGN_CARRIER | GEM_MAC_TX_IGN_COLLIS;
1932 	else if (gigabit != 0) {
1933 		rxcfg |= GEM_MAC_RX_CARR_EXTEND;
1934 		txcfg |= GEM_MAC_TX_CARR_EXTEND;
1935 	}
1936 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG, 0);
1937 	GEM_BANK1_BARRIER(sc, GEM_MAC_TX_CONFIG, 4,
1938 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1939 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0))
1940 		device_printf(sc->sc_dev, "cannot disable TX MAC\n");
1941 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG, txcfg);
1942 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, 0);
1943 	GEM_BANK1_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
1944 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1945 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0))
1946 		device_printf(sc->sc_dev, "cannot disable RX MAC\n");
1947 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, rxcfg);
1948 
1949 	v = GEM_BANK1_READ_4(sc, GEM_MAC_CONTROL_CONFIG) &
1950 	    ~(GEM_MAC_CC_RX_PAUSE | GEM_MAC_CC_TX_PAUSE);
1951 #ifdef notyet
1952 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
1953 	    IFM_ETH_RXPAUSE) != 0)
1954 		v |= GEM_MAC_CC_RX_PAUSE;
1955 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
1956 	    IFM_ETH_TXPAUSE) != 0)
1957 		v |= GEM_MAC_CC_TX_PAUSE;
1958 #endif
1959 	GEM_BANK1_WRITE_4(sc, GEM_MAC_CONTROL_CONFIG, v);
1960 
1961 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) == 0 &&
1962 	    gigabit != 0)
1963 		GEM_BANK1_WRITE_4(sc, GEM_MAC_SLOT_TIME,
1964 		    GEM_MAC_SLOT_TIME_CARR_EXTEND);
1965 	else
1966 		GEM_BANK1_WRITE_4(sc, GEM_MAC_SLOT_TIME,
1967 		    GEM_MAC_SLOT_TIME_NORMAL);
1968 
1969 	/* XIF Configuration */
1970 	v = GEM_MAC_XIF_LINK_LED;
1971 	v |= GEM_MAC_XIF_TX_MII_ENA;
1972 	if ((sc->sc_flags & GEM_SERDES) == 0) {
1973 		if ((GEM_BANK1_READ_4(sc, GEM_MIF_CONFIG) &
1974 		    GEM_MIF_CONFIG_PHY_SEL) != 0 &&
1975 		    (IFM_OPTIONS(sc->sc_mii->mii_media_active) &
1976 		    IFM_FDX) == 0)
1977 			/* External MII needs echo disable if half duplex. */
1978 			v |= GEM_MAC_XIF_ECHO_DISABL;
1979 		else
1980 			/*
1981 			 * Internal MII needs buffer enable.
1982 			 * XXX buffer enable makes only sense for an
1983 			 * external PHY.
1984 			 */
1985 			v |= GEM_MAC_XIF_MII_BUF_ENA;
1986 	}
1987 	if (gigabit != 0)
1988 		v |= GEM_MAC_XIF_GMII_MODE;
1989 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) != 0)
1990 		v |= GEM_MAC_XIF_FDPLX_LED;
1991 	GEM_BANK1_WRITE_4(sc, GEM_MAC_XIF_CONFIG, v);
1992 
1993 	if ((sc->sc_ifp->if_drv_flags & IFF_DRV_RUNNING) != 0 &&
1994 	    (sc->sc_flags & GEM_LINK) != 0) {
1995 		GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG,
1996 		    txcfg | GEM_MAC_TX_ENABLE);
1997 		GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG,
1998 		    rxcfg | GEM_MAC_RX_ENABLE);
1999 	}
2000 }
2001 
2002 int
2003 gem_mediachange(struct ifnet *ifp)
2004 {
2005 	struct gem_softc *sc = ifp->if_softc;
2006 	int error;
2007 
2008 	/* XXX add support for serial media. */
2009 
2010 	GEM_LOCK(sc);
2011 	error = mii_mediachg(sc->sc_mii);
2012 	GEM_UNLOCK(sc);
2013 	return (error);
2014 }
2015 
2016 void
2017 gem_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
2018 {
2019 	struct gem_softc *sc = ifp->if_softc;
2020 
2021 	GEM_LOCK(sc);
2022 	if ((ifp->if_flags & IFF_UP) == 0) {
2023 		GEM_UNLOCK(sc);
2024 		return;
2025 	}
2026 
2027 	mii_pollstat(sc->sc_mii);
2028 	ifmr->ifm_active = sc->sc_mii->mii_media_active;
2029 	ifmr->ifm_status = sc->sc_mii->mii_media_status;
2030 	GEM_UNLOCK(sc);
2031 }
2032 
2033 static int
2034 gem_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
2035 {
2036 	struct gem_softc *sc = ifp->if_softc;
2037 	struct ifreq *ifr = (struct ifreq *)data;
2038 	int error;
2039 
2040 	error = 0;
2041 	switch (cmd) {
2042 	case SIOCSIFFLAGS:
2043 		GEM_LOCK(sc);
2044 		if ((ifp->if_flags & IFF_UP) != 0) {
2045 			if ((ifp->if_drv_flags & IFF_DRV_RUNNING) != 0 &&
2046 			    ((ifp->if_flags ^ sc->sc_ifflags) &
2047 			    (IFF_ALLMULTI | IFF_PROMISC)) != 0)
2048 				gem_setladrf(sc);
2049 			else
2050 				gem_init_locked(sc);
2051 		} else if ((ifp->if_drv_flags & IFF_DRV_RUNNING) != 0)
2052 			gem_stop(ifp, 0);
2053 		if ((ifp->if_flags & IFF_LINK0) != 0)
2054 			sc->sc_csum_features |= CSUM_UDP;
2055 		else
2056 			sc->sc_csum_features &= ~CSUM_UDP;
2057 		if ((ifp->if_capenable & IFCAP_TXCSUM) != 0)
2058 			ifp->if_hwassist = sc->sc_csum_features;
2059 		sc->sc_ifflags = ifp->if_flags;
2060 		GEM_UNLOCK(sc);
2061 		break;
2062 	case SIOCADDMULTI:
2063 	case SIOCDELMULTI:
2064 		GEM_LOCK(sc);
2065 		gem_setladrf(sc);
2066 		GEM_UNLOCK(sc);
2067 		break;
2068 	case SIOCGIFMEDIA:
2069 	case SIOCSIFMEDIA:
2070 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_mii->mii_media, cmd);
2071 		break;
2072 	case SIOCSIFCAP:
2073 		GEM_LOCK(sc);
2074 		ifp->if_capenable = ifr->ifr_reqcap;
2075 		if ((ifp->if_capenable & IFCAP_TXCSUM) != 0)
2076 			ifp->if_hwassist = sc->sc_csum_features;
2077 		else
2078 			ifp->if_hwassist = 0;
2079 		GEM_UNLOCK(sc);
2080 		break;
2081 	default:
2082 		error = ether_ioctl(ifp, cmd, data);
2083 		break;
2084 	}
2085 
2086 	return (error);
2087 }
2088 
2089 static void
2090 gem_setladrf(struct gem_softc *sc)
2091 {
2092 	struct ifnet *ifp = sc->sc_ifp;
2093 	struct ifmultiaddr *inm;
2094 	int i;
2095 	uint32_t hash[16];
2096 	uint32_t crc, v;
2097 
2098 	GEM_LOCK_ASSERT(sc, MA_OWNED);
2099 
2100 	/* Get the current RX configuration. */
2101 	v = GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG);
2102 
2103 	/*
2104 	 * Turn off promiscuous mode, promiscuous group mode (all multicast),
2105 	 * and hash filter.  Depending on the case, the right bit will be
2106 	 * enabled.
2107 	 */
2108 	v &= ~(GEM_MAC_RX_PROMISCUOUS | GEM_MAC_RX_HASH_FILTER |
2109 	    GEM_MAC_RX_PROMISC_GRP);
2110 
2111 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, v);
2112 	GEM_BANK1_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
2113 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
2114 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_HASH_FILTER,
2115 	    0))
2116 		device_printf(sc->sc_dev, "cannot disable RX hash filter\n");
2117 
2118 	if ((ifp->if_flags & IFF_PROMISC) != 0) {
2119 		v |= GEM_MAC_RX_PROMISCUOUS;
2120 		goto chipit;
2121 	}
2122 	if ((ifp->if_flags & IFF_ALLMULTI) != 0) {
2123 		v |= GEM_MAC_RX_PROMISC_GRP;
2124 		goto chipit;
2125 	}
2126 
2127 	/*
2128 	 * Set up multicast address filter by passing all multicast
2129 	 * addresses through a crc generator, and then using the high
2130 	 * order 8 bits as an index into the 256 bit logical address
2131 	 * filter.  The high order 4 bits selects the word, while the
2132 	 * other 4 bits select the bit within the word (where bit 0
2133 	 * is the MSB).
2134 	 */
2135 
2136 	/* Clear the hash table. */
2137 	memset(hash, 0, sizeof(hash));
2138 
2139 	IF_ADDR_LOCK(ifp);
2140 	TAILQ_FOREACH(inm, &ifp->if_multiaddrs, ifma_link) {
2141 		if (inm->ifma_addr->sa_family != AF_LINK)
2142 			continue;
2143 		crc = ether_crc32_le(LLADDR((struct sockaddr_dl *)
2144 		    inm->ifma_addr), ETHER_ADDR_LEN);
2145 
2146 		/* We just want the 8 most significant bits. */
2147 		crc >>= 24;
2148 
2149 		/* Set the corresponding bit in the filter. */
2150 		hash[crc >> 4] |= 1 << (15 - (crc & 15));
2151 	}
2152 	IF_ADDR_UNLOCK(ifp);
2153 
2154 	v |= GEM_MAC_RX_HASH_FILTER;
2155 
2156 	/* Now load the hash table into the chip (if we are using it). */
2157 	for (i = 0; i < 16; i++)
2158 		GEM_BANK1_WRITE_4(sc,
2159 		    GEM_MAC_HASH0 + i * (GEM_MAC_HASH1 - GEM_MAC_HASH0),
2160 		    hash[i]);
2161 
2162  chipit:
2163 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, v);
2164 }
2165