xref: /freebsd/sys/dev/gem/if_gem.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
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, phy;
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 			phy = GEM_PHYAD_EXTERNAL;
298 			break;
299 		default:
300 			phy = MII_PHY_ANY;
301 			break;
302 		}
303 		error = mii_attach(sc->sc_dev, &sc->sc_miibus, ifp,
304 		    gem_mediachange, gem_mediastatus, BMSR_DEFCAPMASK, phy,
305 		    MII_OFFSET_ANY, MIIF_DOPAUSE);
306 	}
307 
308 	/*
309 	 * Fall back on an internal PHY if no external PHY was found.
310 	 * Note that with Apple (K2) GMACs GEM_MIF_CONFIG_MDI0 can't be
311 	 * trusted when the firmware has powered down the chip.
312 	 */
313 	if (error != 0 &&
314 	    ((v & GEM_MIF_CONFIG_MDI0) != 0 || GEM_IS_APPLE(sc))) {
315 		v &= ~GEM_MIF_CONFIG_PHY_SEL;
316 		GEM_BANK1_WRITE_4(sc, GEM_MIF_CONFIG, v);
317 		GEM_BANK1_BARRIER(sc, GEM_MIF_CONFIG, 4,
318 		    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
319 		switch (sc->sc_variant) {
320 		case GEM_SUN_ERI:
321 		case GEM_APPLE_K2_GMAC:
322 			phy = GEM_PHYAD_INTERNAL;
323 			break;
324 		case GEM_APPLE_GMAC:
325 			phy = GEM_PHYAD_EXTERNAL;
326 			break;
327 		default:
328 			phy = MII_PHY_ANY;
329 			break;
330 		}
331 		error = mii_attach(sc->sc_dev, &sc->sc_miibus, ifp,
332 		    gem_mediachange, gem_mediastatus, BMSR_DEFCAPMASK, phy,
333 		    MII_OFFSET_ANY, MIIF_DOPAUSE);
334 	}
335 
336 	/*
337 	 * Try the external PCS SERDES if we didn't find any PHYs.
338 	 */
339 	if (error != 0 && sc->sc_variant == GEM_SUN_GEM) {
340  serdes:
341 		GEM_BANK1_WRITE_4(sc, GEM_MII_DATAPATH_MODE,
342 		    GEM_MII_DATAPATH_SERDES);
343 		GEM_BANK1_BARRIER(sc, GEM_MII_DATAPATH_MODE, 4,
344 		    BUS_SPACE_BARRIER_WRITE);
345 		GEM_BANK1_WRITE_4(sc, GEM_MII_SLINK_CONTROL,
346 		    GEM_MII_SLINK_LOOPBACK | GEM_MII_SLINK_EN_SYNC_D);
347 		GEM_BANK1_BARRIER(sc, GEM_MII_SLINK_CONTROL, 4,
348 		    BUS_SPACE_BARRIER_WRITE);
349 		GEM_BANK1_WRITE_4(sc, GEM_MII_CONFIG, GEM_MII_CONFIG_ENABLE);
350 		GEM_BANK1_BARRIER(sc, GEM_MII_CONFIG, 4,
351 		    BUS_SPACE_BARRIER_WRITE);
352 		sc->sc_flags |= GEM_SERDES;
353 		error = mii_attach(sc->sc_dev, &sc->sc_miibus, ifp,
354 		    gem_mediachange, gem_mediastatus, BMSR_DEFCAPMASK,
355 		    GEM_PHYAD_EXTERNAL, MII_OFFSET_ANY, MIIF_DOPAUSE);
356 	}
357 	if (error != 0) {
358 		device_printf(sc->sc_dev, "attaching PHYs failed\n");
359 		goto fail_rxd;
360 	}
361 	sc->sc_mii = device_get_softc(sc->sc_miibus);
362 
363 	/*
364 	 * From this point forward, the attachment cannot fail.  A failure
365 	 * before this point releases all resources that may have been
366 	 * allocated.
367 	 */
368 
369 	/* Get RX FIFO size. */
370 	sc->sc_rxfifosize = 64 *
371 	    GEM_BANK1_READ_4(sc, GEM_RX_FIFO_SIZE);
372 
373 	/* Get TX FIFO size. */
374 	v = GEM_BANK1_READ_4(sc, GEM_TX_FIFO_SIZE);
375 	device_printf(sc->sc_dev, "%ukB RX FIFO, %ukB TX FIFO\n",
376 	    sc->sc_rxfifosize / 1024, v / 16);
377 
378 	/* Attach the interface. */
379 	ether_ifattach(ifp, sc->sc_enaddr);
380 
381 	/*
382 	 * Tell the upper layer(s) we support long frames/checksum offloads.
383 	 */
384 	ifp->if_data.ifi_hdrlen = sizeof(struct ether_vlan_header);
385 	ifp->if_capabilities |= IFCAP_VLAN_MTU | IFCAP_HWCSUM;
386 	ifp->if_hwassist |= sc->sc_csum_features;
387 	ifp->if_capenable |= IFCAP_VLAN_MTU | IFCAP_HWCSUM;
388 
389 	return (0);
390 
391 	/*
392 	 * Free any resources we've allocated during the failed attach
393 	 * attempt.  Do this in reverse order and fall through.
394 	 */
395  fail_rxd:
396 	for (i = 0; i < GEM_NRXDESC; i++)
397 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
398 			bus_dmamap_destroy(sc->sc_rdmatag,
399 			    sc->sc_rxsoft[i].rxs_dmamap);
400  fail_txd:
401 	for (i = 0; i < GEM_TXQUEUELEN; i++)
402 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
403 			bus_dmamap_destroy(sc->sc_tdmatag,
404 			    sc->sc_txsoft[i].txs_dmamap);
405 	bus_dmamap_unload(sc->sc_cdmatag, sc->sc_cddmamap);
406  fail_cmem:
407 	bus_dmamem_free(sc->sc_cdmatag, sc->sc_control_data,
408 	    sc->sc_cddmamap);
409  fail_ctag:
410 	bus_dma_tag_destroy(sc->sc_cdmatag);
411  fail_ttag:
412 	bus_dma_tag_destroy(sc->sc_tdmatag);
413  fail_rtag:
414 	bus_dma_tag_destroy(sc->sc_rdmatag);
415  fail_ptag:
416 	bus_dma_tag_destroy(sc->sc_pdmatag);
417  fail_ifnet:
418 	if_free(ifp);
419 	return (error);
420 }
421 
422 void
423 gem_detach(struct gem_softc *sc)
424 {
425 	struct ifnet *ifp = sc->sc_ifp;
426 	int i;
427 
428 	ether_ifdetach(ifp);
429 	GEM_LOCK(sc);
430 	gem_stop(ifp, 1);
431 	GEM_UNLOCK(sc);
432 	callout_drain(&sc->sc_tick_ch);
433 #ifdef GEM_RINT_TIMEOUT
434 	callout_drain(&sc->sc_rx_ch);
435 #endif
436 	if_free(ifp);
437 	device_delete_child(sc->sc_dev, sc->sc_miibus);
438 
439 	for (i = 0; i < GEM_NRXDESC; i++)
440 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
441 			bus_dmamap_destroy(sc->sc_rdmatag,
442 			    sc->sc_rxsoft[i].rxs_dmamap);
443 	for (i = 0; i < GEM_TXQUEUELEN; i++)
444 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
445 			bus_dmamap_destroy(sc->sc_tdmatag,
446 			    sc->sc_txsoft[i].txs_dmamap);
447 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
448 	bus_dmamap_unload(sc->sc_cdmatag, sc->sc_cddmamap);
449 	bus_dmamem_free(sc->sc_cdmatag, sc->sc_control_data,
450 	    sc->sc_cddmamap);
451 	bus_dma_tag_destroy(sc->sc_cdmatag);
452 	bus_dma_tag_destroy(sc->sc_tdmatag);
453 	bus_dma_tag_destroy(sc->sc_rdmatag);
454 	bus_dma_tag_destroy(sc->sc_pdmatag);
455 }
456 
457 void
458 gem_suspend(struct gem_softc *sc)
459 {
460 	struct ifnet *ifp = sc->sc_ifp;
461 
462 	GEM_LOCK(sc);
463 	gem_stop(ifp, 0);
464 	GEM_UNLOCK(sc);
465 }
466 
467 void
468 gem_resume(struct gem_softc *sc)
469 {
470 	struct ifnet *ifp = sc->sc_ifp;
471 
472 	GEM_LOCK(sc);
473 	/*
474 	 * On resume all registers have to be initialized again like
475 	 * after power-on.
476 	 */
477 	sc->sc_flags &= ~GEM_INITED;
478 	if (ifp->if_flags & IFF_UP)
479 		gem_init_locked(sc);
480 	GEM_UNLOCK(sc);
481 }
482 
483 static inline void
484 gem_rxcksum(struct mbuf *m, uint64_t flags)
485 {
486 	struct ether_header *eh;
487 	struct ip *ip;
488 	struct udphdr *uh;
489 	uint16_t *opts;
490 	int32_t hlen, len, pktlen;
491 	uint32_t temp32;
492 	uint16_t cksum;
493 
494 	pktlen = m->m_pkthdr.len;
495 	if (pktlen < sizeof(struct ether_header) + sizeof(struct ip))
496 		return;
497 	eh = mtod(m, struct ether_header *);
498 	if (eh->ether_type != htons(ETHERTYPE_IP))
499 		return;
500 	ip = (struct ip *)(eh + 1);
501 	if (ip->ip_v != IPVERSION)
502 		return;
503 
504 	hlen = ip->ip_hl << 2;
505 	pktlen -= sizeof(struct ether_header);
506 	if (hlen < sizeof(struct ip))
507 		return;
508 	if (ntohs(ip->ip_len) < hlen)
509 		return;
510 	if (ntohs(ip->ip_len) != pktlen)
511 		return;
512 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK))
513 		return;	/* Cannot handle fragmented packet. */
514 
515 	switch (ip->ip_p) {
516 	case IPPROTO_TCP:
517 		if (pktlen < (hlen + sizeof(struct tcphdr)))
518 			return;
519 		break;
520 	case IPPROTO_UDP:
521 		if (pktlen < (hlen + sizeof(struct udphdr)))
522 			return;
523 		uh = (struct udphdr *)((uint8_t *)ip + hlen);
524 		if (uh->uh_sum == 0)
525 			return; /* no checksum */
526 		break;
527 	default:
528 		return;
529 	}
530 
531 	cksum = ~(flags & GEM_RD_CHECKSUM);
532 	/* checksum fixup for IP options */
533 	len = hlen - sizeof(struct ip);
534 	if (len > 0) {
535 		opts = (uint16_t *)(ip + 1);
536 		for (; len > 0; len -= sizeof(uint16_t), opts++) {
537 			temp32 = cksum - *opts;
538 			temp32 = (temp32 >> 16) + (temp32 & 65535);
539 			cksum = temp32 & 65535;
540 		}
541 	}
542 	m->m_pkthdr.csum_flags |= CSUM_DATA_VALID;
543 	m->m_pkthdr.csum_data = cksum;
544 }
545 
546 static void
547 gem_cddma_callback(void *xsc, bus_dma_segment_t *segs, int nsegs, int error)
548 {
549 	struct gem_softc *sc = xsc;
550 
551 	if (error != 0)
552 		return;
553 	if (nsegs != 1)
554 		panic("%s: bad control buffer segment count", __func__);
555 	sc->sc_cddma = segs[0].ds_addr;
556 }
557 
558 static void
559 gem_tick(void *arg)
560 {
561 	struct gem_softc *sc = arg;
562 	struct ifnet *ifp = sc->sc_ifp;
563 	uint32_t v;
564 
565 	GEM_LOCK_ASSERT(sc, MA_OWNED);
566 
567 	/*
568 	 * Unload collision and error counters.
569 	 */
570 	ifp->if_collisions +=
571 	    GEM_BANK1_READ_4(sc, GEM_MAC_NORM_COLL_CNT) +
572 	    GEM_BANK1_READ_4(sc, GEM_MAC_FIRST_COLL_CNT);
573 	v = GEM_BANK1_READ_4(sc, GEM_MAC_EXCESS_COLL_CNT) +
574 	    GEM_BANK1_READ_4(sc, GEM_MAC_LATE_COLL_CNT);
575 	ifp->if_collisions += v;
576 	ifp->if_oerrors += v;
577 	ifp->if_ierrors +=
578 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_LEN_ERR_CNT) +
579 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_ALIGN_ERR) +
580 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CRC_ERR_CNT) +
581 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CODE_VIOL);
582 
583 	/*
584 	 * Then clear the hardware counters.
585 	 */
586 	GEM_BANK1_WRITE_4(sc, GEM_MAC_NORM_COLL_CNT, 0);
587 	GEM_BANK1_WRITE_4(sc, GEM_MAC_FIRST_COLL_CNT, 0);
588 	GEM_BANK1_WRITE_4(sc, GEM_MAC_EXCESS_COLL_CNT, 0);
589 	GEM_BANK1_WRITE_4(sc, GEM_MAC_LATE_COLL_CNT, 0);
590 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_LEN_ERR_CNT, 0);
591 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_ALIGN_ERR, 0);
592 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CRC_ERR_CNT, 0);
593 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CODE_VIOL, 0);
594 
595 	mii_tick(sc->sc_mii);
596 
597 	if (gem_watchdog(sc) == EJUSTRETURN)
598 		return;
599 
600 	callout_reset(&sc->sc_tick_ch, hz, gem_tick, sc);
601 }
602 
603 static int
604 gem_bitwait(struct gem_softc *sc, u_int bank, bus_addr_t r, uint32_t clr,
605     uint32_t set)
606 {
607 	int i;
608 	uint32_t reg;
609 
610 	for (i = GEM_TRIES; i--; DELAY(100)) {
611 		reg = GEM_BANKN_READ_M(bank, 4, sc, r);
612 		if ((reg & clr) == 0 && (reg & set) == set)
613 			return (1);
614 	}
615 	return (0);
616 }
617 
618 static void
619 gem_reset(struct gem_softc *sc)
620 {
621 
622 #ifdef GEM_DEBUG
623 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
624 #endif
625 	gem_reset_rx(sc);
626 	gem_reset_tx(sc);
627 
628 	/* Do a full reset. */
629 	GEM_BANK2_WRITE_4(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX);
630 	GEM_BANK2_BARRIER(sc, GEM_RESET, 4,
631 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
632 	if (!GEM_BANK2_BITWAIT(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX, 0))
633 		device_printf(sc->sc_dev, "cannot reset device\n");
634 }
635 
636 static void
637 gem_rxdrain(struct gem_softc *sc)
638 {
639 	struct gem_rxsoft *rxs;
640 	int i;
641 
642 	for (i = 0; i < GEM_NRXDESC; i++) {
643 		rxs = &sc->sc_rxsoft[i];
644 		if (rxs->rxs_mbuf != NULL) {
645 			bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
646 			    BUS_DMASYNC_POSTREAD);
647 			bus_dmamap_unload(sc->sc_rdmatag, rxs->rxs_dmamap);
648 			m_freem(rxs->rxs_mbuf);
649 			rxs->rxs_mbuf = NULL;
650 		}
651 	}
652 }
653 
654 static void
655 gem_stop(struct ifnet *ifp, int disable)
656 {
657 	struct gem_softc *sc = ifp->if_softc;
658 	struct gem_txsoft *txs;
659 
660 #ifdef GEM_DEBUG
661 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
662 #endif
663 
664 	callout_stop(&sc->sc_tick_ch);
665 #ifdef GEM_RINT_TIMEOUT
666 	callout_stop(&sc->sc_rx_ch);
667 #endif
668 
669 	gem_reset_tx(sc);
670 	gem_reset_rx(sc);
671 
672 	/*
673 	 * Release any queued transmit buffers.
674 	 */
675 	while ((txs = STAILQ_FIRST(&sc->sc_txdirtyq)) != NULL) {
676 		STAILQ_REMOVE_HEAD(&sc->sc_txdirtyq, txs_q);
677 		if (txs->txs_ndescs != 0) {
678 			bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
679 			    BUS_DMASYNC_POSTWRITE);
680 			bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
681 			if (txs->txs_mbuf != NULL) {
682 				m_freem(txs->txs_mbuf);
683 				txs->txs_mbuf = NULL;
684 			}
685 		}
686 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
687 	}
688 
689 	if (disable)
690 		gem_rxdrain(sc);
691 
692 	/*
693 	 * Mark the interface down and cancel the watchdog timer.
694 	 */
695 	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
696 	sc->sc_flags &= ~GEM_LINK;
697 	sc->sc_wdog_timer = 0;
698 }
699 
700 static int
701 gem_reset_rx(struct gem_softc *sc)
702 {
703 
704 	/*
705 	 * Resetting while DMA is in progress can cause a bus hang, so we
706 	 * disable DMA first.
707 	 */
708 	gem_disable_rx(sc);
709 	GEM_BANK1_WRITE_4(sc, GEM_RX_CONFIG, 0);
710 	GEM_BANK1_BARRIER(sc, GEM_RX_CONFIG, 4,
711 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
712 	if (!GEM_BANK1_BITWAIT(sc, GEM_RX_CONFIG, GEM_RX_CONFIG_RXDMA_EN, 0))
713 		device_printf(sc->sc_dev, "cannot disable RX DMA\n");
714 
715 	/* Wait 5ms extra. */
716 	DELAY(5000);
717 
718 	/* Finally, reset the ERX. */
719 	GEM_BANK2_WRITE_4(sc, GEM_RESET, GEM_RESET_RX);
720 	GEM_BANK2_BARRIER(sc, GEM_RESET, 4,
721 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
722 	if (!GEM_BANK2_BITWAIT(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX,
723 	    0)) {
724 		device_printf(sc->sc_dev, "cannot reset receiver\n");
725 		return (1);
726 	}
727 	return (0);
728 }
729 
730 /*
731  * Reset the receiver DMA engine.
732  *
733  * Intended to be used in case of GEM_INTR_RX_TAG_ERR, GEM_MAC_RX_OVERFLOW
734  * etc in order to reset the receiver DMA engine only and not do a full
735  * reset which amongst others also downs the link and clears the FIFOs.
736  */
737 static void
738 gem_reset_rxdma(struct gem_softc *sc)
739 {
740 	int i;
741 
742 	if (gem_reset_rx(sc) != 0) {
743 		sc->sc_ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
744 		return (gem_init_locked(sc));
745 	}
746 	for (i = 0; i < GEM_NRXDESC; i++)
747 		if (sc->sc_rxsoft[i].rxs_mbuf != NULL)
748 			GEM_UPDATE_RXDESC(sc, i);
749 	sc->sc_rxptr = 0;
750 	GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
751 
752 	/* NOTE: we use only 32-bit DMA addresses here. */
753 	GEM_BANK1_WRITE_4(sc, GEM_RX_RING_PTR_HI, 0);
754 	GEM_BANK1_WRITE_4(sc, GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
755 	GEM_BANK1_WRITE_4(sc, GEM_RX_KICK, GEM_NRXDESC - 4);
756 	GEM_BANK1_WRITE_4(sc, GEM_RX_CONFIG,
757 	    gem_ringsize(GEM_NRXDESC /* XXX */) |
758 	    ((ETHER_HDR_LEN + sizeof(struct ip)) <<
759 	    GEM_RX_CONFIG_CXM_START_SHFT) |
760 	    (GEM_THRSH_1024 << GEM_RX_CONFIG_FIFO_THRS_SHIFT) |
761 	    (ETHER_ALIGN << GEM_RX_CONFIG_FBOFF_SHFT));
762 	/* Adjust for the SBus clock probably isn't worth the fuzz. */
763 	GEM_BANK1_WRITE_4(sc, GEM_RX_BLANKING,
764 	    ((6 * (sc->sc_flags & GEM_PCI66) != 0 ? 2 : 1) <<
765 	    GEM_RX_BLANKING_TIME_SHIFT) | 6);
766 	GEM_BANK1_WRITE_4(sc, GEM_RX_PAUSE_THRESH,
767 	    (3 * sc->sc_rxfifosize / 256) |
768 	    ((sc->sc_rxfifosize / 256) << 12));
769 	GEM_BANK1_WRITE_4(sc, GEM_RX_CONFIG,
770 	    GEM_BANK1_READ_4(sc, GEM_RX_CONFIG) | GEM_RX_CONFIG_RXDMA_EN);
771 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_MASK,
772 	    GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT);
773 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG,
774 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG) | GEM_MAC_RX_ENABLE);
775 }
776 
777 static int
778 gem_reset_tx(struct gem_softc *sc)
779 {
780 
781 	/*
782 	 * Resetting while DMA is in progress can cause a bus hang, so we
783 	 * disable DMA first.
784 	 */
785 	gem_disable_tx(sc);
786 	GEM_BANK1_WRITE_4(sc, GEM_TX_CONFIG, 0);
787 	GEM_BANK1_BARRIER(sc, GEM_TX_CONFIG, 4,
788 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
789 	if (!GEM_BANK1_BITWAIT(sc, GEM_TX_CONFIG, GEM_TX_CONFIG_TXDMA_EN, 0))
790 		device_printf(sc->sc_dev, "cannot disable TX DMA\n");
791 
792 	/* Wait 5ms extra. */
793 	DELAY(5000);
794 
795 	/* Finally, reset the ETX. */
796 	GEM_BANK2_WRITE_4(sc, GEM_RESET, GEM_RESET_TX);
797 	GEM_BANK2_BARRIER(sc, GEM_RESET, 4,
798 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
799 	if (!GEM_BANK2_BITWAIT(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX,
800 	    0)) {
801 		device_printf(sc->sc_dev, "cannot reset transmitter\n");
802 		return (1);
803 	}
804 	return (0);
805 }
806 
807 static int
808 gem_disable_rx(struct gem_softc *sc)
809 {
810 
811 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG,
812 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG) & ~GEM_MAC_RX_ENABLE);
813 	GEM_BANK1_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
814 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
815 	return (GEM_BANK1_BITWAIT(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE,
816 	    0));
817 }
818 
819 static int
820 gem_disable_tx(struct gem_softc *sc)
821 {
822 
823 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG,
824 	    GEM_BANK1_READ_4(sc, GEM_MAC_TX_CONFIG) & ~GEM_MAC_TX_ENABLE);
825 	GEM_BANK1_BARRIER(sc, GEM_MAC_TX_CONFIG, 4,
826 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
827 	return (GEM_BANK1_BITWAIT(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE,
828 	    0));
829 }
830 
831 static int
832 gem_meminit(struct gem_softc *sc)
833 {
834 	struct gem_rxsoft *rxs;
835 	int error, i;
836 
837 	GEM_LOCK_ASSERT(sc, MA_OWNED);
838 
839 	/*
840 	 * Initialize the transmit descriptor ring.
841 	 */
842 	for (i = 0; i < GEM_NTXDESC; i++) {
843 		sc->sc_txdescs[i].gd_flags = 0;
844 		sc->sc_txdescs[i].gd_addr = 0;
845 	}
846 	sc->sc_txfree = GEM_MAXTXFREE;
847 	sc->sc_txnext = 0;
848 	sc->sc_txwin = 0;
849 
850 	/*
851 	 * Initialize the receive descriptor and receive job
852 	 * descriptor rings.
853 	 */
854 	for (i = 0; i < GEM_NRXDESC; i++) {
855 		rxs = &sc->sc_rxsoft[i];
856 		if (rxs->rxs_mbuf == NULL) {
857 			if ((error = gem_add_rxbuf(sc, i)) != 0) {
858 				device_printf(sc->sc_dev,
859 				    "unable to allocate or map RX buffer %d, "
860 				    "error = %d\n", i, error);
861 				/*
862 				 * XXX we should attempt to run with fewer
863 				 * receive buffers instead of just failing.
864 				 */
865 				gem_rxdrain(sc);
866 				return (1);
867 			}
868 		} else
869 			GEM_INIT_RXDESC(sc, i);
870 	}
871 	sc->sc_rxptr = 0;
872 
873 	GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
874 
875 	return (0);
876 }
877 
878 static u_int
879 gem_ringsize(u_int sz)
880 {
881 
882 	switch (sz) {
883 	case 32:
884 		return (GEM_RING_SZ_32);
885 	case 64:
886 		return (GEM_RING_SZ_64);
887 	case 128:
888 		return (GEM_RING_SZ_128);
889 	case 256:
890 		return (GEM_RING_SZ_256);
891 	case 512:
892 		return (GEM_RING_SZ_512);
893 	case 1024:
894 		return (GEM_RING_SZ_1024);
895 	case 2048:
896 		return (GEM_RING_SZ_2048);
897 	case 4096:
898 		return (GEM_RING_SZ_4096);
899 	case 8192:
900 		return (GEM_RING_SZ_8192);
901 	default:
902 		printf("%s: invalid ring size %d\n", __func__, sz);
903 		return (GEM_RING_SZ_32);
904 	}
905 }
906 
907 static void
908 gem_init(void *xsc)
909 {
910 	struct gem_softc *sc = xsc;
911 
912 	GEM_LOCK(sc);
913 	gem_init_locked(sc);
914 	GEM_UNLOCK(sc);
915 }
916 
917 /*
918  * Initialization of interface; set up initialization block
919  * and transmit/receive descriptor rings.
920  */
921 static void
922 gem_init_locked(struct gem_softc *sc)
923 {
924 	struct ifnet *ifp = sc->sc_ifp;
925 	uint32_t v;
926 
927 	GEM_LOCK_ASSERT(sc, MA_OWNED);
928 
929 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) != 0)
930 		return;
931 
932 #ifdef GEM_DEBUG
933 	CTR2(KTR_GEM, "%s: %s: calling stop", device_get_name(sc->sc_dev),
934 	    __func__);
935 #endif
936 	/*
937 	 * Initialization sequence.  The numbered steps below correspond
938 	 * to the sequence outlined in section 6.3.5.1 in the Ethernet
939 	 * Channel Engine manual (part of the PCIO manual).
940 	 * See also the STP2002-STQ document from Sun Microsystems.
941 	 */
942 
943 	/* step 1 & 2.  Reset the Ethernet Channel. */
944 	gem_stop(ifp, 0);
945 	gem_reset(sc);
946 #ifdef GEM_DEBUG
947 	CTR2(KTR_GEM, "%s: %s: restarting", device_get_name(sc->sc_dev),
948 	    __func__);
949 #endif
950 
951 	if ((sc->sc_flags & GEM_SERDES) == 0)
952 		/* Re-initialize the MIF. */
953 		gem_mifinit(sc);
954 
955 	/* step 3.  Setup data structures in host memory. */
956 	if (gem_meminit(sc) != 0)
957 		return;
958 
959 	/* step 4.  TX MAC registers & counters */
960 	gem_init_regs(sc);
961 
962 	/* step 5.  RX MAC registers & counters */
963 	gem_setladrf(sc);
964 
965 	/* step 6 & 7.  Program Descriptor Ring Base Addresses. */
966 	/* NOTE: we use only 32-bit DMA addresses here. */
967 	GEM_BANK1_WRITE_4(sc, GEM_TX_RING_PTR_HI, 0);
968 	GEM_BANK1_WRITE_4(sc, GEM_TX_RING_PTR_LO, GEM_CDTXADDR(sc, 0));
969 
970 	GEM_BANK1_WRITE_4(sc, GEM_RX_RING_PTR_HI, 0);
971 	GEM_BANK1_WRITE_4(sc, GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
972 #ifdef GEM_DEBUG
973 	CTR3(KTR_GEM, "loading RX ring %lx, TX ring %lx, cddma %lx",
974 	    GEM_CDRXADDR(sc, 0), GEM_CDTXADDR(sc, 0), sc->sc_cddma);
975 #endif
976 
977 	/* step 8.  Global Configuration & Interrupt Mask */
978 
979 	/*
980 	 * Set the internal arbitration to "infinite" bursts of the
981 	 * maximum length of 31 * 64 bytes so DMA transfers aren't
982 	 * split up in cache line size chunks.  This greatly improves
983 	 * RX performance.
984 	 * Enable silicon bug workarounds for the Apple variants.
985 	 */
986 	GEM_BANK1_WRITE_4(sc, GEM_CONFIG,
987 	    GEM_CONFIG_TXDMA_LIMIT | GEM_CONFIG_RXDMA_LIMIT |
988 	    ((sc->sc_flags & GEM_PCI) != 0 ? GEM_CONFIG_BURST_INF :
989 	    GEM_CONFIG_BURST_64) | (GEM_IS_APPLE(sc) ?
990 	    GEM_CONFIG_RONPAULBIT | GEM_CONFIG_BUG2FIX : 0));
991 
992 	GEM_BANK1_WRITE_4(sc, GEM_INTMASK,
993 	    ~(GEM_INTR_TX_INTME | GEM_INTR_TX_EMPTY | GEM_INTR_RX_DONE |
994 	    GEM_INTR_RX_NOBUF | GEM_INTR_RX_TAG_ERR | GEM_INTR_PERR |
995 	    GEM_INTR_BERR
996 #ifdef GEM_DEBUG
997 	    | GEM_INTR_PCS | GEM_INTR_MIF
998 #endif
999 	    ));
1000 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_MASK,
1001 	    GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT);
1002 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_MASK,
1003 	    GEM_MAC_TX_XMIT_DONE | GEM_MAC_TX_DEFER_EXP |
1004 	    GEM_MAC_TX_PEAK_EXP);
1005 #ifdef GEM_DEBUG
1006 	GEM_BANK1_WRITE_4(sc, GEM_MAC_CONTROL_MASK,
1007 	    ~(GEM_MAC_PAUSED | GEM_MAC_PAUSE | GEM_MAC_RESUME));
1008 #else
1009 	GEM_BANK1_WRITE_4(sc, GEM_MAC_CONTROL_MASK,
1010 	    GEM_MAC_PAUSED | GEM_MAC_PAUSE | GEM_MAC_RESUME);
1011 #endif
1012 
1013 	/* step 9.  ETX Configuration: use mostly default values. */
1014 
1015 	/* Enable DMA. */
1016 	v = gem_ringsize(GEM_NTXDESC);
1017 	/* Set TX FIFO threshold and enable DMA. */
1018 	v |= ((sc->sc_variant == GEM_SUN_ERI ? 0x100 : 0x4ff) << 10) &
1019 	    GEM_TX_CONFIG_TXFIFO_TH;
1020 	GEM_BANK1_WRITE_4(sc, GEM_TX_CONFIG, v | GEM_TX_CONFIG_TXDMA_EN);
1021 
1022 	/* step 10.  ERX Configuration */
1023 
1024 	/* Encode Receive Descriptor ring size. */
1025 	v = gem_ringsize(GEM_NRXDESC /* XXX */);
1026 	/* RX TCP/UDP checksum offset */
1027 	v |= ((ETHER_HDR_LEN + sizeof(struct ip)) <<
1028 	    GEM_RX_CONFIG_CXM_START_SHFT);
1029 	/* Set RX FIFO threshold, set first byte offset and enable DMA. */
1030 	GEM_BANK1_WRITE_4(sc, GEM_RX_CONFIG,
1031 	    v | (GEM_THRSH_1024 << GEM_RX_CONFIG_FIFO_THRS_SHIFT) |
1032 	    (ETHER_ALIGN << GEM_RX_CONFIG_FBOFF_SHFT) |
1033 	    GEM_RX_CONFIG_RXDMA_EN);
1034 
1035 	/* Adjust for the SBus clock probably isn't worth the fuzz. */
1036 	GEM_BANK1_WRITE_4(sc, GEM_RX_BLANKING,
1037 	    ((6 * (sc->sc_flags & GEM_PCI66) != 0 ? 2 : 1) <<
1038 	    GEM_RX_BLANKING_TIME_SHIFT) | 6);
1039 
1040 	/*
1041 	 * The following value is for an OFF Threshold of about 3/4 full
1042 	 * and an ON Threshold of 1/4 full.
1043 	 */
1044 	GEM_BANK1_WRITE_4(sc, GEM_RX_PAUSE_THRESH,
1045 	    (3 * sc->sc_rxfifosize / 256) |
1046 	    ((sc->sc_rxfifosize / 256) << 12));
1047 
1048 	/* step 11.  Configure Media. */
1049 
1050 	/* step 12.  RX_MAC Configuration Register */
1051 	v = GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG);
1052 	v |= GEM_MAC_RX_ENABLE | GEM_MAC_RX_STRIP_CRC;
1053 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, 0);
1054 	GEM_BANK1_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
1055 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1056 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0))
1057 		device_printf(sc->sc_dev, "cannot configure RX MAC\n");
1058 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, v);
1059 
1060 	/* step 13.  TX_MAC Configuration Register */
1061 	v = GEM_BANK1_READ_4(sc, GEM_MAC_TX_CONFIG);
1062 	v |= GEM_MAC_TX_ENABLE;
1063 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG, 0);
1064 	GEM_BANK1_BARRIER(sc, GEM_MAC_TX_CONFIG, 4,
1065 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1066 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0))
1067 		device_printf(sc->sc_dev, "cannot configure TX MAC\n");
1068 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG, v);
1069 
1070 	/* step 14.  Issue Transmit Pending command. */
1071 
1072 	/* step 15.  Give the receiver a swift kick. */
1073 	GEM_BANK1_WRITE_4(sc, GEM_RX_KICK, GEM_NRXDESC - 4);
1074 
1075 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
1076 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1077 
1078 	mii_mediachg(sc->sc_mii);
1079 
1080 	/* Start the one second timer. */
1081 	sc->sc_wdog_timer = 0;
1082 	callout_reset(&sc->sc_tick_ch, hz, gem_tick, sc);
1083 }
1084 
1085 static int
1086 gem_load_txmbuf(struct gem_softc *sc, struct mbuf **m_head)
1087 {
1088 	bus_dma_segment_t txsegs[GEM_NTXSEGS];
1089 	struct gem_txsoft *txs;
1090 	struct ip *ip;
1091 	struct mbuf *m;
1092 	uint64_t cflags, flags;
1093 	int error, nexttx, nsegs, offset, seg;
1094 
1095 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1096 
1097 	/* Get a work queue entry. */
1098 	if ((txs = STAILQ_FIRST(&sc->sc_txfreeq)) == NULL) {
1099 		/* Ran out of descriptors. */
1100 		return (ENOBUFS);
1101 	}
1102 
1103 	cflags = 0;
1104 	if (((*m_head)->m_pkthdr.csum_flags & sc->sc_csum_features) != 0) {
1105 		if (M_WRITABLE(*m_head) == 0) {
1106 			m = m_dup(*m_head, M_DONTWAIT);
1107 			m_freem(*m_head);
1108 			*m_head = m;
1109 			if (m == NULL)
1110 				return (ENOBUFS);
1111 		}
1112 		offset = sizeof(struct ether_header);
1113 		m = m_pullup(*m_head, offset + sizeof(struct ip));
1114 		if (m == NULL) {
1115 			*m_head = NULL;
1116 			return (ENOBUFS);
1117 		}
1118 		ip = (struct ip *)(mtod(m, caddr_t) + offset);
1119 		offset += (ip->ip_hl << 2);
1120 		cflags = offset << GEM_TD_CXSUM_STARTSHFT |
1121 		    ((offset + m->m_pkthdr.csum_data) <<
1122 		    GEM_TD_CXSUM_STUFFSHFT) | GEM_TD_CXSUM_ENABLE;
1123 		*m_head = m;
1124 	}
1125 
1126 	error = bus_dmamap_load_mbuf_sg(sc->sc_tdmatag, txs->txs_dmamap,
1127 	    *m_head, txsegs, &nsegs, BUS_DMA_NOWAIT);
1128 	if (error == EFBIG) {
1129 		m = m_collapse(*m_head, M_DONTWAIT, GEM_NTXSEGS);
1130 		if (m == NULL) {
1131 			m_freem(*m_head);
1132 			*m_head = NULL;
1133 			return (ENOBUFS);
1134 		}
1135 		*m_head = m;
1136 		error = bus_dmamap_load_mbuf_sg(sc->sc_tdmatag,
1137 		    txs->txs_dmamap, *m_head, txsegs, &nsegs,
1138 		    BUS_DMA_NOWAIT);
1139 		if (error != 0) {
1140 			m_freem(*m_head);
1141 			*m_head = NULL;
1142 			return (error);
1143 		}
1144 	} else if (error != 0)
1145 		return (error);
1146 	/* If nsegs is wrong then the stack is corrupt. */
1147 	KASSERT(nsegs <= GEM_NTXSEGS,
1148 	    ("%s: too many DMA segments (%d)", __func__, nsegs));
1149 	if (nsegs == 0) {
1150 		m_freem(*m_head);
1151 		*m_head = NULL;
1152 		return (EIO);
1153 	}
1154 
1155 	/*
1156 	 * Ensure we have enough descriptors free to describe
1157 	 * the packet.  Note, we always reserve one descriptor
1158 	 * at the end of the ring as a termination point, in
1159 	 * order to prevent wrap-around.
1160 	 */
1161 	if (nsegs > sc->sc_txfree - 1) {
1162 		txs->txs_ndescs = 0;
1163 		bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
1164 		return (ENOBUFS);
1165 	}
1166 
1167 	txs->txs_ndescs = nsegs;
1168 	txs->txs_firstdesc = sc->sc_txnext;
1169 	nexttx = txs->txs_firstdesc;
1170 	for (seg = 0; seg < nsegs; seg++, nexttx = GEM_NEXTTX(nexttx)) {
1171 #ifdef GEM_DEBUG
1172 		CTR6(KTR_GEM,
1173 		    "%s: mapping seg %d (txd %d), len %lx, addr %#lx (%#lx)",
1174 		    __func__, seg, nexttx, txsegs[seg].ds_len,
1175 		    txsegs[seg].ds_addr,
1176 		    GEM_DMA_WRITE(sc, txsegs[seg].ds_addr));
1177 #endif
1178 		sc->sc_txdescs[nexttx].gd_addr =
1179 		    GEM_DMA_WRITE(sc, txsegs[seg].ds_addr);
1180 		KASSERT(txsegs[seg].ds_len < GEM_TD_BUFSIZE,
1181 		    ("%s: segment size too large!", __func__));
1182 		flags = txsegs[seg].ds_len & GEM_TD_BUFSIZE;
1183 		sc->sc_txdescs[nexttx].gd_flags =
1184 		    GEM_DMA_WRITE(sc, flags | cflags);
1185 		txs->txs_lastdesc = nexttx;
1186 	}
1187 
1188 	/* Set EOP on the last descriptor. */
1189 #ifdef GEM_DEBUG
1190 	CTR3(KTR_GEM, "%s: end of packet at segment %d, TX %d",
1191 	    __func__, seg, nexttx);
1192 #endif
1193 	sc->sc_txdescs[txs->txs_lastdesc].gd_flags |=
1194 	    GEM_DMA_WRITE(sc, GEM_TD_END_OF_PACKET);
1195 
1196 	/* Lastly set SOP on the first descriptor. */
1197 #ifdef GEM_DEBUG
1198 	CTR3(KTR_GEM, "%s: start of packet at segment %d, TX %d",
1199 	    __func__, seg, nexttx);
1200 #endif
1201 	if (++sc->sc_txwin > GEM_NTXSEGS * 2 / 3) {
1202 		sc->sc_txwin = 0;
1203 		sc->sc_txdescs[txs->txs_firstdesc].gd_flags |=
1204 		    GEM_DMA_WRITE(sc, GEM_TD_INTERRUPT_ME |
1205 		    GEM_TD_START_OF_PACKET);
1206 	} else
1207 		sc->sc_txdescs[txs->txs_firstdesc].gd_flags |=
1208 		    GEM_DMA_WRITE(sc, GEM_TD_START_OF_PACKET);
1209 
1210 	/* Sync the DMA map. */
1211 	bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
1212 	    BUS_DMASYNC_PREWRITE);
1213 
1214 #ifdef GEM_DEBUG
1215 	CTR4(KTR_GEM, "%s: setting firstdesc=%d, lastdesc=%d, ndescs=%d",
1216 	    __func__, txs->txs_firstdesc, txs->txs_lastdesc,
1217 	    txs->txs_ndescs);
1218 #endif
1219 	STAILQ_REMOVE_HEAD(&sc->sc_txfreeq, txs_q);
1220 	STAILQ_INSERT_TAIL(&sc->sc_txdirtyq, txs, txs_q);
1221 	txs->txs_mbuf = *m_head;
1222 
1223 	sc->sc_txnext = GEM_NEXTTX(txs->txs_lastdesc);
1224 	sc->sc_txfree -= txs->txs_ndescs;
1225 
1226 	return (0);
1227 }
1228 
1229 static void
1230 gem_init_regs(struct gem_softc *sc)
1231 {
1232 	const u_char *laddr = IF_LLADDR(sc->sc_ifp);
1233 
1234 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1235 
1236 	/* These registers are not cleared on reset. */
1237 	if ((sc->sc_flags & GEM_INITED) == 0) {
1238 		/* magic values */
1239 		GEM_BANK1_WRITE_4(sc, GEM_MAC_IPG0, 0);
1240 		GEM_BANK1_WRITE_4(sc, GEM_MAC_IPG1, 8);
1241 		GEM_BANK1_WRITE_4(sc, GEM_MAC_IPG2, 4);
1242 
1243 		/* min frame length */
1244 		GEM_BANK1_WRITE_4(sc, GEM_MAC_MAC_MIN_FRAME, ETHER_MIN_LEN);
1245 		/* max frame length and max burst size */
1246 		GEM_BANK1_WRITE_4(sc, GEM_MAC_MAC_MAX_FRAME,
1247 		    (ETHER_MAX_LEN + ETHER_VLAN_ENCAP_LEN) | (0x2000 << 16));
1248 
1249 		/* more magic values */
1250 		GEM_BANK1_WRITE_4(sc, GEM_MAC_PREAMBLE_LEN, 0x7);
1251 		GEM_BANK1_WRITE_4(sc, GEM_MAC_JAM_SIZE, 0x4);
1252 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ATTEMPT_LIMIT, 0x10);
1253 		GEM_BANK1_WRITE_4(sc, GEM_MAC_CONTROL_TYPE, 0x8808);
1254 
1255 		/* random number seed */
1256 		GEM_BANK1_WRITE_4(sc, GEM_MAC_RANDOM_SEED,
1257 		    ((laddr[5] << 8) | laddr[4]) & 0x3ff);
1258 
1259 		/* secondary MAC address: 0:0:0:0:0:0 */
1260 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR3, 0);
1261 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR4, 0);
1262 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR5, 0);
1263 
1264 		/* MAC control address: 01:80:c2:00:00:01 */
1265 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR6, 0x0001);
1266 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR7, 0xc200);
1267 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR8, 0x0180);
1268 
1269 		/* MAC filter address: 0:0:0:0:0:0 */
1270 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR_FILTER0, 0);
1271 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR_FILTER1, 0);
1272 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR_FILTER2, 0);
1273 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADR_FLT_MASK1_2, 0);
1274 		GEM_BANK1_WRITE_4(sc, GEM_MAC_ADR_FLT_MASK0, 0);
1275 
1276 		sc->sc_flags |= GEM_INITED;
1277 	}
1278 
1279 	/* Counters need to be zeroed. */
1280 	GEM_BANK1_WRITE_4(sc, GEM_MAC_NORM_COLL_CNT, 0);
1281 	GEM_BANK1_WRITE_4(sc, GEM_MAC_FIRST_COLL_CNT, 0);
1282 	GEM_BANK1_WRITE_4(sc, GEM_MAC_EXCESS_COLL_CNT, 0);
1283 	GEM_BANK1_WRITE_4(sc, GEM_MAC_LATE_COLL_CNT, 0);
1284 	GEM_BANK1_WRITE_4(sc, GEM_MAC_DEFER_TMR_CNT, 0);
1285 	GEM_BANK1_WRITE_4(sc, GEM_MAC_PEAK_ATTEMPTS, 0);
1286 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_FRAME_COUNT, 0);
1287 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_LEN_ERR_CNT, 0);
1288 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_ALIGN_ERR, 0);
1289 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CRC_ERR_CNT, 0);
1290 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CODE_VIOL, 0);
1291 
1292 	/* Set XOFF PAUSE time. */
1293 	GEM_BANK1_WRITE_4(sc, GEM_MAC_SEND_PAUSE_CMD, 0x1BF0);
1294 
1295 	/* Set the station address. */
1296 	GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR0, (laddr[4] << 8) | laddr[5]);
1297 	GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR1, (laddr[2] << 8) | laddr[3]);
1298 	GEM_BANK1_WRITE_4(sc, GEM_MAC_ADDR2, (laddr[0] << 8) | laddr[1]);
1299 
1300 	/* Enable MII outputs. */
1301 	GEM_BANK1_WRITE_4(sc, GEM_MAC_XIF_CONFIG, GEM_MAC_XIF_TX_MII_ENA);
1302 }
1303 
1304 static void
1305 gem_start(struct ifnet *ifp)
1306 {
1307 	struct gem_softc *sc = ifp->if_softc;
1308 
1309 	GEM_LOCK(sc);
1310 	gem_start_locked(ifp);
1311 	GEM_UNLOCK(sc);
1312 }
1313 
1314 static inline void
1315 gem_txkick(struct gem_softc *sc)
1316 {
1317 
1318 	/*
1319 	 * Update the TX kick register.  This register has to point to the
1320 	 * descriptor after the last valid one and for optimum performance
1321 	 * should be incremented in multiples of 4 (the DMA engine fetches/
1322 	 * updates descriptors in batches of 4).
1323 	 */
1324 #ifdef GEM_DEBUG
1325 	CTR3(KTR_GEM, "%s: %s: kicking TX %d",
1326 	    device_get_name(sc->sc_dev), __func__, sc->sc_txnext);
1327 #endif
1328 	GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
1329 	GEM_BANK1_WRITE_4(sc, GEM_TX_KICK, sc->sc_txnext);
1330 }
1331 
1332 static void
1333 gem_start_locked(struct ifnet *ifp)
1334 {
1335 	struct gem_softc *sc = ifp->if_softc;
1336 	struct mbuf *m;
1337 	int kicked, ntx;
1338 
1339 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1340 
1341 	if ((ifp->if_drv_flags & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
1342 	    IFF_DRV_RUNNING || (sc->sc_flags & GEM_LINK) == 0)
1343 		return;
1344 
1345 #ifdef GEM_DEBUG
1346 	CTR4(KTR_GEM, "%s: %s: txfree %d, txnext %d",
1347 	    device_get_name(sc->sc_dev), __func__, sc->sc_txfree,
1348 	    sc->sc_txnext);
1349 #endif
1350 	ntx = 0;
1351 	kicked = 0;
1352 	for (; !IFQ_DRV_IS_EMPTY(&ifp->if_snd) && sc->sc_txfree > 1;) {
1353 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
1354 		if (m == NULL)
1355 			break;
1356 		if (gem_load_txmbuf(sc, &m) != 0) {
1357 			if (m == NULL)
1358 				break;
1359 			ifp->if_drv_flags |= IFF_DRV_OACTIVE;
1360 			IFQ_DRV_PREPEND(&ifp->if_snd, m);
1361 			break;
1362 		}
1363 		if ((sc->sc_txnext % 4) == 0) {
1364 			gem_txkick(sc);
1365 			kicked = 1;
1366 		} else
1367 			kicked = 0;
1368 		ntx++;
1369 		BPF_MTAP(ifp, m);
1370 	}
1371 
1372 	if (ntx > 0) {
1373 		if (kicked == 0)
1374 			gem_txkick(sc);
1375 #ifdef GEM_DEBUG
1376 		CTR2(KTR_GEM, "%s: packets enqueued, OWN on %d",
1377 		    device_get_name(sc->sc_dev), sc->sc_txnext);
1378 #endif
1379 
1380 		/* Set a watchdog timer in case the chip flakes out. */
1381 		sc->sc_wdog_timer = 5;
1382 #ifdef GEM_DEBUG
1383 		CTR3(KTR_GEM, "%s: %s: watchdog %d",
1384 		    device_get_name(sc->sc_dev), __func__,
1385 		    sc->sc_wdog_timer);
1386 #endif
1387 	}
1388 }
1389 
1390 static void
1391 gem_tint(struct gem_softc *sc)
1392 {
1393 	struct ifnet *ifp = sc->sc_ifp;
1394 	struct gem_txsoft *txs;
1395 	int progress;
1396 	uint32_t txlast;
1397 #ifdef GEM_DEBUG
1398 	int i;
1399 
1400 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1401 
1402 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
1403 #endif
1404 
1405 	/*
1406 	 * Go through our TX list and free mbufs for those
1407 	 * frames that have been transmitted.
1408 	 */
1409 	progress = 0;
1410 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD);
1411 	while ((txs = STAILQ_FIRST(&sc->sc_txdirtyq)) != NULL) {
1412 #ifdef GEM_DEBUG
1413 		if ((ifp->if_flags & IFF_DEBUG) != 0) {
1414 			printf("    txsoft %p transmit chain:\n", txs);
1415 			for (i = txs->txs_firstdesc;; i = GEM_NEXTTX(i)) {
1416 				printf("descriptor %d: ", i);
1417 				printf("gd_flags: 0x%016llx\t",
1418 				    (long long)GEM_DMA_READ(sc,
1419 				    sc->sc_txdescs[i].gd_flags));
1420 				printf("gd_addr: 0x%016llx\n",
1421 				    (long long)GEM_DMA_READ(sc,
1422 				    sc->sc_txdescs[i].gd_addr));
1423 				if (i == txs->txs_lastdesc)
1424 					break;
1425 			}
1426 		}
1427 #endif
1428 
1429 		/*
1430 		 * In theory, we could harvest some descriptors before
1431 		 * the ring is empty, but that's a bit complicated.
1432 		 *
1433 		 * GEM_TX_COMPLETION points to the last descriptor
1434 		 * processed + 1.
1435 		 */
1436 		txlast = GEM_BANK1_READ_4(sc, GEM_TX_COMPLETION);
1437 #ifdef GEM_DEBUG
1438 		CTR4(KTR_GEM, "%s: txs->txs_firstdesc = %d, "
1439 		    "txs->txs_lastdesc = %d, txlast = %d",
1440 		    __func__, txs->txs_firstdesc, txs->txs_lastdesc, txlast);
1441 #endif
1442 		if (txs->txs_firstdesc <= txs->txs_lastdesc) {
1443 			if ((txlast >= txs->txs_firstdesc) &&
1444 			    (txlast <= txs->txs_lastdesc))
1445 				break;
1446 		} else {
1447 			/* Ick -- this command wraps. */
1448 			if ((txlast >= txs->txs_firstdesc) ||
1449 			    (txlast <= txs->txs_lastdesc))
1450 				break;
1451 		}
1452 
1453 #ifdef GEM_DEBUG
1454 		CTR1(KTR_GEM, "%s: releasing a descriptor", __func__);
1455 #endif
1456 		STAILQ_REMOVE_HEAD(&sc->sc_txdirtyq, txs_q);
1457 
1458 		sc->sc_txfree += txs->txs_ndescs;
1459 
1460 		bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
1461 		    BUS_DMASYNC_POSTWRITE);
1462 		bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
1463 		if (txs->txs_mbuf != NULL) {
1464 			m_freem(txs->txs_mbuf);
1465 			txs->txs_mbuf = NULL;
1466 		}
1467 
1468 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
1469 
1470 		ifp->if_opackets++;
1471 		progress = 1;
1472 	}
1473 
1474 #ifdef GEM_DEBUG
1475 	CTR4(KTR_GEM, "%s: GEM_TX_STATE_MACHINE %x GEM_TX_DATA_PTR %llx "
1476 	    "GEM_TX_COMPLETION %x",
1477 	    __func__, GEM_BANK1_READ_4(sc, GEM_TX_STATE_MACHINE),
1478 	    ((long long)GEM_BANK1_READ_4(sc, GEM_TX_DATA_PTR_HI) << 32) |
1479 	    GEM_BANK1_READ_4(sc, GEM_TX_DATA_PTR_LO),
1480 	    GEM_BANK1_READ_4(sc, GEM_TX_COMPLETION));
1481 #endif
1482 
1483 	if (progress) {
1484 		if (sc->sc_txfree == GEM_NTXDESC - 1)
1485 			sc->sc_txwin = 0;
1486 
1487 		/*
1488 		 * We freed some descriptors, so reset IFF_DRV_OACTIVE
1489 		 * and restart.
1490 		 */
1491 		ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1492 		if (STAILQ_EMPTY(&sc->sc_txdirtyq))
1493 		    sc->sc_wdog_timer = 0;
1494 		gem_start_locked(ifp);
1495 	}
1496 
1497 #ifdef GEM_DEBUG
1498 	CTR3(KTR_GEM, "%s: %s: watchdog %d",
1499 	    device_get_name(sc->sc_dev), __func__, sc->sc_wdog_timer);
1500 #endif
1501 }
1502 
1503 #ifdef GEM_RINT_TIMEOUT
1504 static void
1505 gem_rint_timeout(void *arg)
1506 {
1507 	struct gem_softc *sc = arg;
1508 
1509 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1510 
1511 	gem_rint(sc);
1512 }
1513 #endif
1514 
1515 static void
1516 gem_rint(struct gem_softc *sc)
1517 {
1518 	struct ifnet *ifp = sc->sc_ifp;
1519 	struct mbuf *m;
1520 	uint64_t rxstat;
1521 	uint32_t rxcomp;
1522 
1523 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1524 
1525 #ifdef GEM_RINT_TIMEOUT
1526 	callout_stop(&sc->sc_rx_ch);
1527 #endif
1528 #ifdef GEM_DEBUG
1529 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
1530 #endif
1531 
1532 	/*
1533 	 * Read the completion register once.  This limits
1534 	 * how long the following loop can execute.
1535 	 */
1536 	rxcomp = GEM_BANK1_READ_4(sc, GEM_RX_COMPLETION);
1537 #ifdef GEM_DEBUG
1538 	CTR3(KTR_GEM, "%s: sc->sc_rxptr %d, complete %d",
1539 	    __func__, sc->sc_rxptr, rxcomp);
1540 #endif
1541 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
1542 	for (; sc->sc_rxptr != rxcomp;) {
1543 		m = sc->sc_rxsoft[sc->sc_rxptr].rxs_mbuf;
1544 		rxstat = GEM_DMA_READ(sc,
1545 		    sc->sc_rxdescs[sc->sc_rxptr].gd_flags);
1546 
1547 		if (rxstat & GEM_RD_OWN) {
1548 #ifdef GEM_RINT_TIMEOUT
1549 			/*
1550 			 * The descriptor is still marked as owned, although
1551 			 * it is supposed to have completed.  This has been
1552 			 * observed on some machines.  Just exiting here
1553 			 * might leave the packet sitting around until another
1554 			 * one arrives to trigger a new interrupt, which is
1555 			 * generally undesirable, so set up a timeout.
1556 			 */
1557 			callout_reset(&sc->sc_rx_ch, GEM_RXOWN_TICKS,
1558 			    gem_rint_timeout, sc);
1559 #endif
1560 			m = NULL;
1561 			goto kickit;
1562 		}
1563 
1564 		if (rxstat & GEM_RD_BAD_CRC) {
1565 			ifp->if_ierrors++;
1566 			device_printf(sc->sc_dev, "receive error: CRC error\n");
1567 			GEM_INIT_RXDESC(sc, sc->sc_rxptr);
1568 			m = NULL;
1569 			goto kickit;
1570 		}
1571 
1572 #ifdef GEM_DEBUG
1573 		if ((ifp->if_flags & IFF_DEBUG) != 0) {
1574 			printf("    rxsoft %p descriptor %d: ",
1575 			    &sc->sc_rxsoft[sc->sc_rxptr], sc->sc_rxptr);
1576 			printf("gd_flags: 0x%016llx\t",
1577 			    (long long)GEM_DMA_READ(sc,
1578 			    sc->sc_rxdescs[sc->sc_rxptr].gd_flags));
1579 			printf("gd_addr: 0x%016llx\n",
1580 			    (long long)GEM_DMA_READ(sc,
1581 			    sc->sc_rxdescs[sc->sc_rxptr].gd_addr));
1582 		}
1583 #endif
1584 
1585 		/*
1586 		 * Allocate a new mbuf cluster.  If that fails, we are
1587 		 * out of memory, and must drop the packet and recycle
1588 		 * the buffer that's already attached to this descriptor.
1589 		 */
1590 		if (gem_add_rxbuf(sc, sc->sc_rxptr) != 0) {
1591 			ifp->if_ierrors++;
1592 			GEM_INIT_RXDESC(sc, sc->sc_rxptr);
1593 			m = NULL;
1594 		}
1595 
1596  kickit:
1597 		/*
1598 		 * Update the RX kick register.  This register has to point
1599 		 * to the descriptor after the last valid one (before the
1600 		 * current batch) and for optimum performance should be
1601 		 * incremented in multiples of 4 (the DMA engine fetches/
1602 		 * updates descriptors in batches of 4).
1603 		 */
1604 		sc->sc_rxptr = GEM_NEXTRX(sc->sc_rxptr);
1605 		if ((sc->sc_rxptr % 4) == 0) {
1606 			GEM_CDSYNC(sc,
1607 			    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
1608 			GEM_BANK1_WRITE_4(sc, GEM_RX_KICK,
1609 			    (sc->sc_rxptr + GEM_NRXDESC - 4) &
1610 			    GEM_NRXDESC_MASK);
1611 		}
1612 
1613 		if (m == NULL) {
1614 			if (rxstat & GEM_RD_OWN)
1615 				break;
1616 			continue;
1617 		}
1618 
1619 		ifp->if_ipackets++;
1620 		m->m_data += ETHER_ALIGN; /* first byte offset */
1621 		m->m_pkthdr.rcvif = ifp;
1622 		m->m_pkthdr.len = m->m_len = GEM_RD_BUFLEN(rxstat);
1623 
1624 		if ((ifp->if_capenable & IFCAP_RXCSUM) != 0)
1625 			gem_rxcksum(m, rxstat);
1626 
1627 		/* Pass it on. */
1628 		GEM_UNLOCK(sc);
1629 		(*ifp->if_input)(ifp, m);
1630 		GEM_LOCK(sc);
1631 	}
1632 
1633 #ifdef GEM_DEBUG
1634 	CTR3(KTR_GEM, "%s: done sc->sc_rxptr %d, complete %d", __func__,
1635 	    sc->sc_rxptr, GEM_BANK1_READ_4(sc, GEM_RX_COMPLETION));
1636 #endif
1637 }
1638 
1639 static int
1640 gem_add_rxbuf(struct gem_softc *sc, int idx)
1641 {
1642 	struct gem_rxsoft *rxs = &sc->sc_rxsoft[idx];
1643 	struct mbuf *m;
1644 	bus_dma_segment_t segs[1];
1645 	int error, nsegs;
1646 
1647 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1648 
1649 	m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
1650 	if (m == NULL)
1651 		return (ENOBUFS);
1652 	m->m_len = m->m_pkthdr.len = m->m_ext.ext_size;
1653 
1654 #ifdef GEM_DEBUG
1655 	/* Bzero the packet to check DMA. */
1656 	memset(m->m_ext.ext_buf, 0, m->m_ext.ext_size);
1657 #endif
1658 
1659 	if (rxs->rxs_mbuf != NULL) {
1660 		bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
1661 		    BUS_DMASYNC_POSTREAD);
1662 		bus_dmamap_unload(sc->sc_rdmatag, rxs->rxs_dmamap);
1663 	}
1664 
1665 	error = bus_dmamap_load_mbuf_sg(sc->sc_rdmatag, rxs->rxs_dmamap,
1666 	    m, segs, &nsegs, BUS_DMA_NOWAIT);
1667 	if (error != 0) {
1668 		device_printf(sc->sc_dev,
1669 		    "cannot load RS DMA map %d, error = %d\n", idx, error);
1670 		m_freem(m);
1671 		return (error);
1672 	}
1673 	/* If nsegs is wrong then the stack is corrupt. */
1674 	KASSERT(nsegs == 1,
1675 	    ("%s: too many DMA segments (%d)", __func__, nsegs));
1676 	rxs->rxs_mbuf = m;
1677 	rxs->rxs_paddr = segs[0].ds_addr;
1678 
1679 	bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
1680 	    BUS_DMASYNC_PREREAD);
1681 
1682 	GEM_INIT_RXDESC(sc, idx);
1683 
1684 	return (0);
1685 }
1686 
1687 static void
1688 gem_eint(struct gem_softc *sc, u_int status)
1689 {
1690 
1691 	sc->sc_ifp->if_ierrors++;
1692 	if ((status & GEM_INTR_RX_TAG_ERR) != 0) {
1693 		gem_reset_rxdma(sc);
1694 		return;
1695 	}
1696 
1697 	device_printf(sc->sc_dev, "%s: status 0x%x", __func__, status);
1698 	if ((status & GEM_INTR_BERR) != 0) {
1699 		if ((sc->sc_flags & GEM_PCI) != 0)
1700 			printf(", PCI bus error 0x%x\n",
1701 			    GEM_BANK1_READ_4(sc, GEM_PCI_ERROR_STATUS));
1702 		else
1703 			printf(", SBus error 0x%x\n",
1704 			    GEM_BANK1_READ_4(sc, GEM_SBUS_STATUS));
1705 	}
1706 }
1707 
1708 void
1709 gem_intr(void *v)
1710 {
1711 	struct gem_softc *sc = v;
1712 	uint32_t status, status2;
1713 
1714 	GEM_LOCK(sc);
1715 	status = GEM_BANK1_READ_4(sc, GEM_STATUS);
1716 
1717 #ifdef GEM_DEBUG
1718 	CTR4(KTR_GEM, "%s: %s: cplt %x, status %x",
1719 	    device_get_name(sc->sc_dev), __func__,
1720 	    (status >> GEM_STATUS_TX_COMPLETION_SHFT), (u_int)status);
1721 
1722 	/*
1723 	 * PCS interrupts must be cleared, otherwise no traffic is passed!
1724 	 */
1725 	if ((status & GEM_INTR_PCS) != 0) {
1726 		status2 =
1727 		    GEM_BANK1_READ_4(sc, GEM_MII_INTERRUP_STATUS) |
1728 		    GEM_BANK1_READ_4(sc, GEM_MII_INTERRUP_STATUS);
1729 		if ((status2 & GEM_MII_INTERRUP_LINK) != 0)
1730 			device_printf(sc->sc_dev,
1731 			    "%s: PCS link status changed\n", __func__);
1732 	}
1733 	if ((status & GEM_MAC_CONTROL_STATUS) != 0) {
1734 		status2 = GEM_BANK1_READ_4(sc, GEM_MAC_CONTROL_STATUS);
1735 		if ((status2 & GEM_MAC_PAUSED) != 0)
1736 			device_printf(sc->sc_dev,
1737 			    "%s: PAUSE received (PAUSE time %d slots)\n",
1738 			    __func__, GEM_MAC_PAUSE_TIME(status2));
1739 		if ((status2 & GEM_MAC_PAUSE) != 0)
1740 			device_printf(sc->sc_dev,
1741 			    "%s: transited to PAUSE state\n", __func__);
1742 		if ((status2 & GEM_MAC_RESUME) != 0)
1743 			device_printf(sc->sc_dev,
1744 			    "%s: transited to non-PAUSE state\n", __func__);
1745 	}
1746 	if ((status & GEM_INTR_MIF) != 0)
1747 		device_printf(sc->sc_dev, "%s: MIF interrupt\n", __func__);
1748 #endif
1749 
1750 	if (__predict_false(status &
1751 	    (GEM_INTR_RX_TAG_ERR | GEM_INTR_PERR | GEM_INTR_BERR)) != 0)
1752 		gem_eint(sc, status);
1753 
1754 	if ((status & (GEM_INTR_RX_DONE | GEM_INTR_RX_NOBUF)) != 0)
1755 		gem_rint(sc);
1756 
1757 	if ((status & (GEM_INTR_TX_EMPTY | GEM_INTR_TX_INTME)) != 0)
1758 		gem_tint(sc);
1759 
1760 	if (__predict_false((status & GEM_INTR_TX_MAC) != 0)) {
1761 		status2 = GEM_BANK1_READ_4(sc, GEM_MAC_TX_STATUS);
1762 		if ((status2 &
1763 		    ~(GEM_MAC_TX_XMIT_DONE | GEM_MAC_TX_DEFER_EXP |
1764 		    GEM_MAC_TX_PEAK_EXP)) != 0)
1765 			device_printf(sc->sc_dev,
1766 			    "MAC TX fault, status %x\n", status2);
1767 		if ((status2 &
1768 		    (GEM_MAC_TX_UNDERRUN | GEM_MAC_TX_PKT_TOO_LONG)) != 0) {
1769 			sc->sc_ifp->if_oerrors++;
1770 			sc->sc_ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1771 			gem_init_locked(sc);
1772 		}
1773 	}
1774 	if (__predict_false((status & GEM_INTR_RX_MAC) != 0)) {
1775 		status2 = GEM_BANK1_READ_4(sc, GEM_MAC_RX_STATUS);
1776 		/*
1777 		 * At least with GEM_SUN_GEM and some GEM_SUN_ERI
1778 		 * revisions GEM_MAC_RX_OVERFLOW happen often due to a
1779 		 * silicon bug so handle them silently.  Moreover, it's
1780 		 * likely that the receiver has hung so we reset it.
1781 		 */
1782 		if ((status2 & GEM_MAC_RX_OVERFLOW) != 0) {
1783 			sc->sc_ifp->if_ierrors++;
1784 			gem_reset_rxdma(sc);
1785 		} else if ((status2 &
1786 		    ~(GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT)) != 0)
1787 			device_printf(sc->sc_dev,
1788 			    "MAC RX fault, status %x\n", status2);
1789 	}
1790 	GEM_UNLOCK(sc);
1791 }
1792 
1793 static int
1794 gem_watchdog(struct gem_softc *sc)
1795 {
1796 	struct ifnet *ifp = sc->sc_ifp;
1797 
1798 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1799 
1800 #ifdef GEM_DEBUG
1801 	CTR4(KTR_GEM,
1802 	    "%s: GEM_RX_CONFIG %x GEM_MAC_RX_STATUS %x GEM_MAC_RX_CONFIG %x",
1803 	    __func__, GEM_BANK1_READ_4(sc, GEM_RX_CONFIG),
1804 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_STATUS),
1805 	    GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG));
1806 	CTR4(KTR_GEM,
1807 	    "%s: GEM_TX_CONFIG %x GEM_MAC_TX_STATUS %x GEM_MAC_TX_CONFIG %x",
1808 	    __func__, GEM_BANK1_READ_4(sc, GEM_TX_CONFIG),
1809 	    GEM_BANK1_READ_4(sc, GEM_MAC_TX_STATUS),
1810 	    GEM_BANK1_READ_4(sc, GEM_MAC_TX_CONFIG));
1811 #endif
1812 
1813 	if (sc->sc_wdog_timer == 0 || --sc->sc_wdog_timer != 0)
1814 		return (0);
1815 
1816 	if ((sc->sc_flags & GEM_LINK) != 0)
1817 		device_printf(sc->sc_dev, "device timeout\n");
1818 	else if (bootverbose)
1819 		device_printf(sc->sc_dev, "device timeout (no link)\n");
1820 	++ifp->if_oerrors;
1821 
1822 	/* Try to get more packets going. */
1823 	ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1824 	gem_init_locked(sc);
1825 	gem_start_locked(ifp);
1826 	return (EJUSTRETURN);
1827 }
1828 
1829 static void
1830 gem_mifinit(struct gem_softc *sc)
1831 {
1832 
1833 	/* Configure the MIF in frame mode. */
1834 	GEM_BANK1_WRITE_4(sc, GEM_MIF_CONFIG,
1835 	    GEM_BANK1_READ_4(sc, GEM_MIF_CONFIG) & ~GEM_MIF_CONFIG_BB_ENA);
1836 	GEM_BANK1_BARRIER(sc, GEM_MIF_CONFIG, 4,
1837 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1838 }
1839 
1840 /*
1841  * MII interface
1842  *
1843  * The MII interface supports at least three different operating modes:
1844  *
1845  * Bitbang mode is implemented using data, clock and output enable registers.
1846  *
1847  * Frame mode is implemented by loading a complete frame into the frame
1848  * register and polling the valid bit for completion.
1849  *
1850  * Polling mode uses the frame register but completion is indicated by
1851  * an interrupt.
1852  *
1853  */
1854 int
1855 gem_mii_readreg(device_t dev, int phy, int reg)
1856 {
1857 	struct gem_softc *sc;
1858 	int n;
1859 	uint32_t v;
1860 
1861 #ifdef GEM_DEBUG_PHY
1862 	printf("%s: phy %d reg %d\n", __func__, phy, reg);
1863 #endif
1864 
1865 	sc = device_get_softc(dev);
1866 	if ((sc->sc_flags & GEM_SERDES) != 0) {
1867 		switch (reg) {
1868 		case MII_BMCR:
1869 			reg = GEM_MII_CONTROL;
1870 			break;
1871 		case MII_BMSR:
1872 			reg = GEM_MII_STATUS;
1873 			break;
1874 		case MII_PHYIDR1:
1875 		case MII_PHYIDR2:
1876 			return (0);
1877 		case MII_ANAR:
1878 			reg = GEM_MII_ANAR;
1879 			break;
1880 		case MII_ANLPAR:
1881 			reg = GEM_MII_ANLPAR;
1882 			break;
1883 		case MII_EXTSR:
1884 			return (EXTSR_1000XFDX | EXTSR_1000XHDX);
1885 		default:
1886 			device_printf(sc->sc_dev,
1887 			    "%s: unhandled register %d\n", __func__, reg);
1888 			return (0);
1889 		}
1890 		return (GEM_BANK1_READ_4(sc, reg));
1891 	}
1892 
1893 	/* Construct the frame command. */
1894 	v = GEM_MIF_FRAME_READ |
1895 	    (phy << GEM_MIF_PHY_SHIFT) |
1896 	    (reg << GEM_MIF_REG_SHIFT);
1897 
1898 	GEM_BANK1_WRITE_4(sc, GEM_MIF_FRAME, v);
1899 	GEM_BANK1_BARRIER(sc, GEM_MIF_FRAME, 4,
1900 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1901 	for (n = 0; n < 100; n++) {
1902 		DELAY(1);
1903 		v = GEM_BANK1_READ_4(sc, GEM_MIF_FRAME);
1904 		if (v & GEM_MIF_FRAME_TA0)
1905 			return (v & GEM_MIF_FRAME_DATA);
1906 	}
1907 
1908 	device_printf(sc->sc_dev, "%s: timed out\n", __func__);
1909 	return (0);
1910 }
1911 
1912 int
1913 gem_mii_writereg(device_t dev, int phy, int reg, int val)
1914 {
1915 	struct gem_softc *sc;
1916 	int n;
1917 	uint32_t v;
1918 
1919 #ifdef GEM_DEBUG_PHY
1920 	printf("%s: phy %d reg %d val %x\n", phy, reg, val, __func__);
1921 #endif
1922 
1923 	sc = device_get_softc(dev);
1924 	if ((sc->sc_flags & GEM_SERDES) != 0) {
1925 		switch (reg) {
1926 		case MII_BMSR:
1927 			reg = GEM_MII_STATUS;
1928 			break;
1929 		case MII_BMCR:
1930 			reg = GEM_MII_CONTROL;
1931 			if ((val & GEM_MII_CONTROL_RESET) == 0)
1932 				break;
1933 			GEM_BANK1_WRITE_4(sc, GEM_MII_CONTROL, val);
1934 			GEM_BANK1_BARRIER(sc, GEM_MII_CONTROL, 4,
1935 			    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1936 			if (!GEM_BANK1_BITWAIT(sc, GEM_MII_CONTROL,
1937 			    GEM_MII_CONTROL_RESET, 0))
1938 				device_printf(sc->sc_dev,
1939 				    "cannot reset PCS\n");
1940 			/* FALLTHROUGH */
1941 		case MII_ANAR:
1942 			GEM_BANK1_WRITE_4(sc, GEM_MII_CONFIG, 0);
1943 			GEM_BANK1_BARRIER(sc, GEM_MII_CONFIG, 4,
1944 			    BUS_SPACE_BARRIER_WRITE);
1945 			GEM_BANK1_WRITE_4(sc, GEM_MII_ANAR, val);
1946 			GEM_BANK1_BARRIER(sc, GEM_MII_ANAR, 4,
1947 			    BUS_SPACE_BARRIER_WRITE);
1948 			GEM_BANK1_WRITE_4(sc, GEM_MII_SLINK_CONTROL,
1949 			    GEM_MII_SLINK_LOOPBACK | GEM_MII_SLINK_EN_SYNC_D);
1950 			GEM_BANK1_BARRIER(sc, GEM_MII_SLINK_CONTROL, 4,
1951 			    BUS_SPACE_BARRIER_WRITE);
1952 			GEM_BANK1_WRITE_4(sc, GEM_MII_CONFIG,
1953 			    GEM_MII_CONFIG_ENABLE);
1954 			GEM_BANK1_BARRIER(sc, GEM_MII_CONFIG, 4,
1955 			    BUS_SPACE_BARRIER_WRITE);
1956 			return (0);
1957 		case MII_ANLPAR:
1958 			reg = GEM_MII_ANLPAR;
1959 			break;
1960 		default:
1961 			device_printf(sc->sc_dev,
1962 			    "%s: unhandled register %d\n", __func__, reg);
1963 			return (0);
1964 		}
1965 		GEM_BANK1_WRITE_4(sc, reg, val);
1966 		GEM_BANK1_BARRIER(sc, reg, 4,
1967 		    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1968 		return (0);
1969 	}
1970 
1971 	/* Construct the frame command. */
1972 	v = GEM_MIF_FRAME_WRITE |
1973 	    (phy << GEM_MIF_PHY_SHIFT) |
1974 	    (reg << GEM_MIF_REG_SHIFT) |
1975 	    (val & GEM_MIF_FRAME_DATA);
1976 
1977 	GEM_BANK1_WRITE_4(sc, GEM_MIF_FRAME, v);
1978 	GEM_BANK1_BARRIER(sc, GEM_MIF_FRAME, 4,
1979 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1980 	for (n = 0; n < 100; n++) {
1981 		DELAY(1);
1982 		v = GEM_BANK1_READ_4(sc, GEM_MIF_FRAME);
1983 		if (v & GEM_MIF_FRAME_TA0)
1984 			return (1);
1985 	}
1986 
1987 	device_printf(sc->sc_dev, "%s: timed out\n", __func__);
1988 	return (0);
1989 }
1990 
1991 void
1992 gem_mii_statchg(device_t dev)
1993 {
1994 	struct gem_softc *sc;
1995 	int gigabit;
1996 	uint32_t rxcfg, txcfg, v;
1997 
1998 	sc = device_get_softc(dev);
1999 
2000 	GEM_LOCK_ASSERT(sc, MA_OWNED);
2001 
2002 #ifdef GEM_DEBUG
2003 	if ((sc->sc_ifp->if_flags & IFF_DEBUG) != 0)
2004 		device_printf(sc->sc_dev, "%s: status change\n", __func__);
2005 #endif
2006 
2007 	if ((sc->sc_mii->mii_media_status & IFM_ACTIVE) != 0 &&
2008 	    IFM_SUBTYPE(sc->sc_mii->mii_media_active) != IFM_NONE)
2009 		sc->sc_flags |= GEM_LINK;
2010 	else
2011 		sc->sc_flags &= ~GEM_LINK;
2012 
2013 	switch (IFM_SUBTYPE(sc->sc_mii->mii_media_active)) {
2014 	case IFM_1000_SX:
2015 	case IFM_1000_LX:
2016 	case IFM_1000_CX:
2017 	case IFM_1000_T:
2018 		gigabit = 1;
2019 		break;
2020 	default:
2021 		gigabit = 0;
2022 	}
2023 
2024 	/*
2025 	 * The configuration done here corresponds to the steps F) and
2026 	 * G) and as far as enabling of RX and TX MAC goes also step H)
2027 	 * of the initialization sequence outlined in section 3.2.1 of
2028 	 * the GEM Gigabit Ethernet ASIC Specification.
2029 	 */
2030 
2031 	rxcfg = GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG);
2032 	rxcfg &= ~(GEM_MAC_RX_CARR_EXTEND | GEM_MAC_RX_ENABLE);
2033 	txcfg = GEM_MAC_TX_ENA_IPG0 | GEM_MAC_TX_NGU | GEM_MAC_TX_NGU_LIMIT;
2034 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) != 0)
2035 		txcfg |= GEM_MAC_TX_IGN_CARRIER | GEM_MAC_TX_IGN_COLLIS;
2036 	else if (gigabit != 0) {
2037 		rxcfg |= GEM_MAC_RX_CARR_EXTEND;
2038 		txcfg |= GEM_MAC_TX_CARR_EXTEND;
2039 	}
2040 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG, 0);
2041 	GEM_BANK1_BARRIER(sc, GEM_MAC_TX_CONFIG, 4,
2042 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
2043 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0))
2044 		device_printf(sc->sc_dev, "cannot disable TX MAC\n");
2045 	GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG, txcfg);
2046 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, 0);
2047 	GEM_BANK1_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
2048 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
2049 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0))
2050 		device_printf(sc->sc_dev, "cannot disable RX MAC\n");
2051 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, rxcfg);
2052 
2053 	v = GEM_BANK1_READ_4(sc, GEM_MAC_CONTROL_CONFIG) &
2054 	    ~(GEM_MAC_CC_RX_PAUSE | GEM_MAC_CC_TX_PAUSE);
2055 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
2056 	    IFM_ETH_RXPAUSE) != 0)
2057 		v |= GEM_MAC_CC_RX_PAUSE;
2058 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
2059 	    IFM_ETH_TXPAUSE) != 0)
2060 		v |= GEM_MAC_CC_TX_PAUSE;
2061 	GEM_BANK1_WRITE_4(sc, GEM_MAC_CONTROL_CONFIG, v);
2062 
2063 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) == 0 &&
2064 	    gigabit != 0)
2065 		GEM_BANK1_WRITE_4(sc, GEM_MAC_SLOT_TIME,
2066 		    GEM_MAC_SLOT_TIME_CARR_EXTEND);
2067 	else
2068 		GEM_BANK1_WRITE_4(sc, GEM_MAC_SLOT_TIME,
2069 		    GEM_MAC_SLOT_TIME_NORMAL);
2070 
2071 	/* XIF Configuration */
2072 	v = GEM_MAC_XIF_LINK_LED;
2073 	v |= GEM_MAC_XIF_TX_MII_ENA;
2074 	if ((sc->sc_flags & GEM_SERDES) == 0) {
2075 		if ((GEM_BANK1_READ_4(sc, GEM_MIF_CONFIG) &
2076 		    GEM_MIF_CONFIG_PHY_SEL) != 0) {
2077 			/* External MII needs echo disable if half duplex. */
2078 			if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
2079 			    IFM_FDX) == 0)
2080 				v |= GEM_MAC_XIF_ECHO_DISABL;
2081 		} else
2082 			/*
2083 			 * Internal MII needs buffer enable.
2084 			 * XXX buffer enable makes only sense for an
2085 			 * external PHY.
2086 			 */
2087 			v |= GEM_MAC_XIF_MII_BUF_ENA;
2088 	}
2089 	if (gigabit != 0)
2090 		v |= GEM_MAC_XIF_GMII_MODE;
2091 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) != 0)
2092 		v |= GEM_MAC_XIF_FDPLX_LED;
2093 	GEM_BANK1_WRITE_4(sc, GEM_MAC_XIF_CONFIG, v);
2094 
2095 	if ((sc->sc_ifp->if_drv_flags & IFF_DRV_RUNNING) != 0 &&
2096 	    (sc->sc_flags & GEM_LINK) != 0) {
2097 		GEM_BANK1_WRITE_4(sc, GEM_MAC_TX_CONFIG,
2098 		    txcfg | GEM_MAC_TX_ENABLE);
2099 		GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG,
2100 		    rxcfg | GEM_MAC_RX_ENABLE);
2101 	}
2102 }
2103 
2104 int
2105 gem_mediachange(struct ifnet *ifp)
2106 {
2107 	struct gem_softc *sc = ifp->if_softc;
2108 	int error;
2109 
2110 	/* XXX add support for serial media. */
2111 
2112 	GEM_LOCK(sc);
2113 	error = mii_mediachg(sc->sc_mii);
2114 	GEM_UNLOCK(sc);
2115 	return (error);
2116 }
2117 
2118 void
2119 gem_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
2120 {
2121 	struct gem_softc *sc = ifp->if_softc;
2122 
2123 	GEM_LOCK(sc);
2124 	if ((ifp->if_flags & IFF_UP) == 0) {
2125 		GEM_UNLOCK(sc);
2126 		return;
2127 	}
2128 
2129 	mii_pollstat(sc->sc_mii);
2130 	ifmr->ifm_active = sc->sc_mii->mii_media_active;
2131 	ifmr->ifm_status = sc->sc_mii->mii_media_status;
2132 	GEM_UNLOCK(sc);
2133 }
2134 
2135 static int
2136 gem_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
2137 {
2138 	struct gem_softc *sc = ifp->if_softc;
2139 	struct ifreq *ifr = (struct ifreq *)data;
2140 	int error;
2141 
2142 	error = 0;
2143 	switch (cmd) {
2144 	case SIOCSIFFLAGS:
2145 		GEM_LOCK(sc);
2146 		if ((ifp->if_flags & IFF_UP) != 0) {
2147 			if ((ifp->if_drv_flags & IFF_DRV_RUNNING) != 0 &&
2148 			    ((ifp->if_flags ^ sc->sc_ifflags) &
2149 			    (IFF_ALLMULTI | IFF_PROMISC)) != 0)
2150 				gem_setladrf(sc);
2151 			else
2152 				gem_init_locked(sc);
2153 		} else if ((ifp->if_drv_flags & IFF_DRV_RUNNING) != 0)
2154 			gem_stop(ifp, 0);
2155 		if ((ifp->if_flags & IFF_LINK0) != 0)
2156 			sc->sc_csum_features |= CSUM_UDP;
2157 		else
2158 			sc->sc_csum_features &= ~CSUM_UDP;
2159 		if ((ifp->if_capenable & IFCAP_TXCSUM) != 0)
2160 			ifp->if_hwassist = sc->sc_csum_features;
2161 		sc->sc_ifflags = ifp->if_flags;
2162 		GEM_UNLOCK(sc);
2163 		break;
2164 	case SIOCADDMULTI:
2165 	case SIOCDELMULTI:
2166 		GEM_LOCK(sc);
2167 		gem_setladrf(sc);
2168 		GEM_UNLOCK(sc);
2169 		break;
2170 	case SIOCGIFMEDIA:
2171 	case SIOCSIFMEDIA:
2172 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_mii->mii_media, cmd);
2173 		break;
2174 	case SIOCSIFCAP:
2175 		GEM_LOCK(sc);
2176 		ifp->if_capenable = ifr->ifr_reqcap;
2177 		if ((ifp->if_capenable & IFCAP_TXCSUM) != 0)
2178 			ifp->if_hwassist = sc->sc_csum_features;
2179 		else
2180 			ifp->if_hwassist = 0;
2181 		GEM_UNLOCK(sc);
2182 		break;
2183 	default:
2184 		error = ether_ioctl(ifp, cmd, data);
2185 		break;
2186 	}
2187 
2188 	return (error);
2189 }
2190 
2191 static void
2192 gem_setladrf(struct gem_softc *sc)
2193 {
2194 	struct ifnet *ifp = sc->sc_ifp;
2195 	struct ifmultiaddr *inm;
2196 	int i;
2197 	uint32_t hash[16];
2198 	uint32_t crc, v;
2199 
2200 	GEM_LOCK_ASSERT(sc, MA_OWNED);
2201 
2202 	/* Get the current RX configuration. */
2203 	v = GEM_BANK1_READ_4(sc, GEM_MAC_RX_CONFIG);
2204 
2205 	/*
2206 	 * Turn off promiscuous mode, promiscuous group mode (all multicast),
2207 	 * and hash filter.  Depending on the case, the right bit will be
2208 	 * enabled.
2209 	 */
2210 	v &= ~(GEM_MAC_RX_PROMISCUOUS | GEM_MAC_RX_HASH_FILTER |
2211 	    GEM_MAC_RX_PROMISC_GRP);
2212 
2213 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, v);
2214 	GEM_BANK1_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
2215 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
2216 	if (!GEM_BANK1_BITWAIT(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_HASH_FILTER,
2217 	    0))
2218 		device_printf(sc->sc_dev, "cannot disable RX hash filter\n");
2219 
2220 	if ((ifp->if_flags & IFF_PROMISC) != 0) {
2221 		v |= GEM_MAC_RX_PROMISCUOUS;
2222 		goto chipit;
2223 	}
2224 	if ((ifp->if_flags & IFF_ALLMULTI) != 0) {
2225 		v |= GEM_MAC_RX_PROMISC_GRP;
2226 		goto chipit;
2227 	}
2228 
2229 	/*
2230 	 * Set up multicast address filter by passing all multicast
2231 	 * addresses through a crc generator, and then using the high
2232 	 * order 8 bits as an index into the 256 bit logical address
2233 	 * filter.  The high order 4 bits selects the word, while the
2234 	 * other 4 bits select the bit within the word (where bit 0
2235 	 * is the MSB).
2236 	 */
2237 
2238 	/* Clear the hash table. */
2239 	memset(hash, 0, sizeof(hash));
2240 
2241 	if_maddr_rlock(ifp);
2242 	TAILQ_FOREACH(inm, &ifp->if_multiaddrs, ifma_link) {
2243 		if (inm->ifma_addr->sa_family != AF_LINK)
2244 			continue;
2245 		crc = ether_crc32_le(LLADDR((struct sockaddr_dl *)
2246 		    inm->ifma_addr), ETHER_ADDR_LEN);
2247 
2248 		/* We just want the 8 most significant bits. */
2249 		crc >>= 24;
2250 
2251 		/* Set the corresponding bit in the filter. */
2252 		hash[crc >> 4] |= 1 << (15 - (crc & 15));
2253 	}
2254 	if_maddr_runlock(ifp);
2255 
2256 	v |= GEM_MAC_RX_HASH_FILTER;
2257 
2258 	/* Now load the hash table into the chip (if we are using it). */
2259 	for (i = 0; i < 16; i++)
2260 		GEM_BANK1_WRITE_4(sc,
2261 		    GEM_MAC_HASH0 + i * (GEM_MAC_HASH1 - GEM_MAC_HASH0),
2262 		    hash[i]);
2263 
2264  chipit:
2265 	GEM_BANK1_WRITE_4(sc, GEM_MAC_RX_CONFIG, v);
2266 }
2267