xref: /freebsd/sys/dev/gem/if_gem.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
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, bus_addr_t r, uint32_t clr,
100 		    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_txcksum(struct gem_softc *sc, struct mbuf *m,
131 		    uint64_t *cflags);
132 static int	gem_watchdog(struct gem_softc *sc);
133 
134 devclass_t gem_devclass;
135 DRIVER_MODULE(miibus, gem, miibus_driver, miibus_devclass, 0, 0);
136 MODULE_DEPEND(gem, miibus, 1, 1, 1);
137 
138 #ifdef GEM_DEBUG
139 #include <sys/ktr.h>
140 #define	KTR_GEM		KTR_CT2
141 #endif
142 
143 int
144 gem_attach(struct gem_softc *sc)
145 {
146 	struct gem_txsoft *txs;
147 	struct ifnet *ifp;
148 	int error, i;
149 	uint32_t v;
150 
151 	ifp = sc->sc_ifp = if_alloc(IFT_ETHER);
152 	if (ifp == NULL)
153 		return (ENOSPC);
154 
155 	callout_init_mtx(&sc->sc_tick_ch, &sc->sc_mtx, 0);
156 #ifdef GEM_RINT_TIMEOUT
157 	callout_init_mtx(&sc->sc_rx_ch, &sc->sc_mtx, 0);
158 #endif
159 
160 	/* Make sure the chip is stopped. */
161 	ifp->if_softc = sc;
162 	gem_reset(sc);
163 
164 	error = bus_dma_tag_create(bus_get_dma_tag(sc->sc_dev), 1, 0,
165 	    BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
166 	    BUS_SPACE_MAXSIZE_32BIT, 0, BUS_SPACE_MAXSIZE_32BIT, 0, NULL,
167 	    NULL, &sc->sc_pdmatag);
168 	if (error)
169 		goto fail_ifnet;
170 
171 	error = bus_dma_tag_create(sc->sc_pdmatag, 1, 0,
172 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL, MCLBYTES,
173 	    1, MCLBYTES, BUS_DMA_ALLOCNOW, NULL, NULL, &sc->sc_rdmatag);
174 	if (error)
175 		goto fail_ptag;
176 
177 	error = bus_dma_tag_create(sc->sc_pdmatag, 1, 0,
178 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
179 	    MCLBYTES * GEM_NTXSEGS, GEM_NTXSEGS, MCLBYTES,
180 	    BUS_DMA_ALLOCNOW, NULL, NULL, &sc->sc_tdmatag);
181 	if (error)
182 		goto fail_rtag;
183 
184 	error = bus_dma_tag_create(sc->sc_pdmatag, PAGE_SIZE, 0,
185 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
186 	    sizeof(struct gem_control_data), 1,
187 	    sizeof(struct gem_control_data), 0,
188 	    NULL, NULL, &sc->sc_cdmatag);
189 	if (error)
190 		goto fail_ttag;
191 
192 	/*
193 	 * Allocate the control data structures, create and load the
194 	 * DMA map for it.
195 	 */
196 	if ((error = bus_dmamem_alloc(sc->sc_cdmatag,
197 	    (void **)&sc->sc_control_data,
198 	    BUS_DMA_WAITOK | BUS_DMA_COHERENT | BUS_DMA_ZERO,
199 	    &sc->sc_cddmamap))) {
200 		device_printf(sc->sc_dev,
201 		    "unable to allocate control data, error = %d\n", error);
202 		goto fail_ctag;
203 	}
204 
205 	sc->sc_cddma = 0;
206 	if ((error = bus_dmamap_load(sc->sc_cdmatag, sc->sc_cddmamap,
207 	    sc->sc_control_data, sizeof(struct gem_control_data),
208 	    gem_cddma_callback, sc, 0)) != 0 || sc->sc_cddma == 0) {
209 		device_printf(sc->sc_dev,
210 		    "unable to load control data DMA map, error = %d\n",
211 		    error);
212 		goto fail_cmem;
213 	}
214 
215 	/*
216 	 * Initialize the transmit job descriptors.
217 	 */
218 	STAILQ_INIT(&sc->sc_txfreeq);
219 	STAILQ_INIT(&sc->sc_txdirtyq);
220 
221 	/*
222 	 * Create the transmit buffer DMA maps.
223 	 */
224 	error = ENOMEM;
225 	for (i = 0; i < GEM_TXQUEUELEN; i++) {
226 		txs = &sc->sc_txsoft[i];
227 		txs->txs_mbuf = NULL;
228 		txs->txs_ndescs = 0;
229 		if ((error = bus_dmamap_create(sc->sc_tdmatag, 0,
230 		    &txs->txs_dmamap)) != 0) {
231 			device_printf(sc->sc_dev,
232 			    "unable to create TX DMA map %d, error = %d\n",
233 			    i, error);
234 			goto fail_txd;
235 		}
236 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
237 	}
238 
239 	/*
240 	 * Create the receive buffer DMA maps.
241 	 */
242 	for (i = 0; i < GEM_NRXDESC; i++) {
243 		if ((error = bus_dmamap_create(sc->sc_rdmatag, 0,
244 		    &sc->sc_rxsoft[i].rxs_dmamap)) != 0) {
245 			device_printf(sc->sc_dev,
246 			    "unable to create RX DMA map %d, error = %d\n",
247 			    i, error);
248 			goto fail_rxd;
249 		}
250 		sc->sc_rxsoft[i].rxs_mbuf = NULL;
251 	}
252 
253 	/* Bad things will happen when touching this register on ERI. */
254 	if (sc->sc_variant != GEM_SUN_ERI)
255 		bus_write_4(sc->sc_res[0], GEM_MII_DATAPATH_MODE,
256 		    GEM_MII_DATAPATH_MII);
257 
258 	gem_mifinit(sc);
259 
260 	/*
261 	 * Look for an external PHY.
262 	 */
263 	error = ENXIO;
264 	v = bus_read_4(sc->sc_res[0], GEM_MIF_CONFIG);
265 	if ((v & GEM_MIF_CONFIG_MDI1) != 0) {
266 		v |= GEM_MIF_CONFIG_PHY_SEL;
267 		bus_write_4(sc->sc_res[0], GEM_MIF_CONFIG, v);
268 		switch (sc->sc_variant) {
269 		case GEM_SUN_ERI:
270 			sc->sc_phyad = GEM_PHYAD_EXTERNAL;
271 			break;
272 		default:
273 			sc->sc_phyad = -1;
274 			break;
275 		}
276 		error = mii_phy_probe(sc->sc_dev, &sc->sc_miibus,
277 		    gem_mediachange, gem_mediastatus);
278 	}
279 
280 	/*
281 	 * Fall back on an internal PHY if no external PHY was found.
282 	 */
283 	if (error != 0 && (v & GEM_MIF_CONFIG_MDI0) != 0) {
284 		v &= ~GEM_MIF_CONFIG_PHY_SEL;
285 		bus_write_4(sc->sc_res[0], GEM_MIF_CONFIG, v);
286 		switch (sc->sc_variant) {
287 		case GEM_SUN_ERI:
288 		case GEM_APPLE_K2_GMAC:
289 			sc->sc_phyad = GEM_PHYAD_INTERNAL;
290 			break;
291 		case GEM_APPLE_GMAC:
292 			sc->sc_phyad = GEM_PHYAD_EXTERNAL;
293 			break;
294 		default:
295 			sc->sc_phyad = -1;
296 			break;
297 		}
298 		error = mii_phy_probe(sc->sc_dev, &sc->sc_miibus,
299 		    gem_mediachange, gem_mediastatus);
300 	}
301 
302 	/*
303 	 * Try the external PCS SERDES if we didn't find any PHYs.
304 	 */
305 	if (error != 0 && sc->sc_variant == GEM_SUN_GEM) {
306 		bus_write_4(sc->sc_res[0], GEM_MII_DATAPATH_MODE,
307 		    GEM_MII_DATAPATH_SERDES);
308 		bus_write_4(sc->sc_res[0], GEM_MII_SLINK_CONTROL,
309 		    GEM_MII_SLINK_LOOPBACK | GEM_MII_SLINK_EN_SYNC_D);
310 		bus_write_4(sc->sc_res[0], GEM_MII_CONFIG,
311 		    GEM_MII_CONFIG_ENABLE);
312 		sc->sc_flags |= GEM_SERDES;
313 		sc->sc_phyad = GEM_PHYAD_EXTERNAL;
314 		error = mii_phy_probe(sc->sc_dev, &sc->sc_miibus,
315 		    gem_mediachange, gem_mediastatus);
316 	}
317 
318 	if (error != 0) {
319 		device_printf(sc->sc_dev, "PHY probe failed: %d\n", error);
320 		goto fail_rxd;
321 	}
322 	sc->sc_mii = device_get_softc(sc->sc_miibus);
323 
324 	/*
325 	 * From this point forward, the attachment cannot fail.  A failure
326 	 * before this point releases all resources that may have been
327 	 * allocated.
328 	 */
329 
330 	/* Get RX FIFO size */
331 	sc->sc_rxfifosize = 64 *
332 	    bus_read_4(sc->sc_res[0], GEM_RX_FIFO_SIZE);
333 
334 	/* Get TX FIFO size */
335 	v = bus_read_4(sc->sc_res[0], GEM_TX_FIFO_SIZE);
336 	device_printf(sc->sc_dev, "%ukB RX FIFO, %ukB TX FIFO\n",
337 	    sc->sc_rxfifosize / 1024, v / 16);
338 
339 	sc->sc_csum_features = GEM_CSUM_FEATURES;
340 	/* Initialize ifnet structure. */
341 	ifp->if_softc = sc;
342 	if_initname(ifp, device_get_name(sc->sc_dev),
343 	    device_get_unit(sc->sc_dev));
344 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
345 	ifp->if_start = gem_start;
346 	ifp->if_ioctl = gem_ioctl;
347 	ifp->if_init = gem_init;
348 	IFQ_SET_MAXLEN(&ifp->if_snd, GEM_TXQUEUELEN);
349 	ifp->if_snd.ifq_drv_maxlen = GEM_TXQUEUELEN;
350 	IFQ_SET_READY(&ifp->if_snd);
351 
352 	/* Attach the interface. */
353 	ether_ifattach(ifp, sc->sc_enaddr);
354 
355 	/*
356 	 * Tell the upper layer(s) we support long frames/checksum offloads.
357 	 */
358 	ifp->if_data.ifi_hdrlen = sizeof(struct ether_vlan_header);
359 	ifp->if_capabilities |= IFCAP_VLAN_MTU | IFCAP_HWCSUM;
360 	ifp->if_hwassist |= sc->sc_csum_features;
361 	ifp->if_capenable |= IFCAP_VLAN_MTU | IFCAP_HWCSUM;
362 
363 	return (0);
364 
365 	/*
366 	 * Free any resources we've allocated during the failed attach
367 	 * attempt.  Do this in reverse order and fall through.
368 	 */
369  fail_rxd:
370 	for (i = 0; i < GEM_NRXDESC; i++)
371 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
372 			bus_dmamap_destroy(sc->sc_rdmatag,
373 			    sc->sc_rxsoft[i].rxs_dmamap);
374  fail_txd:
375 	for (i = 0; i < GEM_TXQUEUELEN; i++)
376 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
377 			bus_dmamap_destroy(sc->sc_tdmatag,
378 			    sc->sc_txsoft[i].txs_dmamap);
379 	bus_dmamap_unload(sc->sc_cdmatag, sc->sc_cddmamap);
380  fail_cmem:
381 	bus_dmamem_free(sc->sc_cdmatag, sc->sc_control_data,
382 	    sc->sc_cddmamap);
383  fail_ctag:
384 	bus_dma_tag_destroy(sc->sc_cdmatag);
385  fail_ttag:
386 	bus_dma_tag_destroy(sc->sc_tdmatag);
387  fail_rtag:
388 	bus_dma_tag_destroy(sc->sc_rdmatag);
389  fail_ptag:
390 	bus_dma_tag_destroy(sc->sc_pdmatag);
391  fail_ifnet:
392 	if_free(ifp);
393 	return (error);
394 }
395 
396 void
397 gem_detach(struct gem_softc *sc)
398 {
399 	struct ifnet *ifp = sc->sc_ifp;
400 	int i;
401 
402 	GEM_LOCK(sc);
403 	gem_stop(ifp, 1);
404 	GEM_UNLOCK(sc);
405 	callout_drain(&sc->sc_tick_ch);
406 #ifdef GEM_RINT_TIMEOUT
407 	callout_drain(&sc->sc_rx_ch);
408 #endif
409 	ether_ifdetach(ifp);
410 	if_free(ifp);
411 	device_delete_child(sc->sc_dev, sc->sc_miibus);
412 
413 	for (i = 0; i < GEM_NRXDESC; i++)
414 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
415 			bus_dmamap_destroy(sc->sc_rdmatag,
416 			    sc->sc_rxsoft[i].rxs_dmamap);
417 	for (i = 0; i < GEM_TXQUEUELEN; i++)
418 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
419 			bus_dmamap_destroy(sc->sc_tdmatag,
420 			    sc->sc_txsoft[i].txs_dmamap);
421 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD);
422 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTWRITE);
423 	bus_dmamap_unload(sc->sc_cdmatag, sc->sc_cddmamap);
424 	bus_dmamem_free(sc->sc_cdmatag, sc->sc_control_data,
425 	    sc->sc_cddmamap);
426 	bus_dma_tag_destroy(sc->sc_cdmatag);
427 	bus_dma_tag_destroy(sc->sc_tdmatag);
428 	bus_dma_tag_destroy(sc->sc_rdmatag);
429 	bus_dma_tag_destroy(sc->sc_pdmatag);
430 }
431 
432 void
433 gem_suspend(struct gem_softc *sc)
434 {
435 	struct ifnet *ifp = sc->sc_ifp;
436 
437 	GEM_LOCK(sc);
438 	gem_stop(ifp, 0);
439 	GEM_UNLOCK(sc);
440 }
441 
442 void
443 gem_resume(struct gem_softc *sc)
444 {
445 	struct ifnet *ifp = sc->sc_ifp;
446 
447 	GEM_LOCK(sc);
448 	/*
449 	 * On resume all registers have to be initialized again like
450 	 * after power-on.
451 	 */
452 	sc->sc_flags &= ~GEM_INITED;
453 	if (ifp->if_flags & IFF_UP)
454 		gem_init_locked(sc);
455 	GEM_UNLOCK(sc);
456 }
457 
458 static __inline void
459 gem_txcksum(struct gem_softc *sc, struct mbuf *m, uint64_t *cflags)
460 {
461 	char *p;
462 	struct ip *ip;
463 	struct mbuf *m0;
464 	uint64_t offset, offset2;
465 
466 	m0 = m;
467 	offset = sizeof(struct ip) + ETHER_HDR_LEN;
468 	for(; m && m->m_len == 0; m = m->m_next)
469 		;
470 	if (m == NULL || m->m_len < ETHER_HDR_LEN) {
471 		device_printf(sc->sc_dev, "%s: m_len < ETHER_HDR_LEN\n",
472 		    __func__);
473 		/* Checksum will be corrupted. */
474 		m = m0;
475 		goto sendit;
476 	}
477 	if (m->m_len < ETHER_HDR_LEN + sizeof(uint32_t)) {
478 		if (m->m_len != ETHER_HDR_LEN) {
479 			device_printf(sc->sc_dev,
480 			    "%s: m_len != ETHER_HDR_LEN\n", __func__);
481 			/* Checksum will be corrupted. */
482 			m = m0;
483 			goto sendit;
484 		}
485 		for(m = m->m_next; m && m->m_len == 0; m = m->m_next)
486 			;
487 		if (m == NULL) {
488 			/* Checksum will be corrupted. */
489 			m = m0;
490 			goto sendit;
491 		}
492 		ip = mtod(m, struct ip *);
493 	} else {
494 		p = mtod(m, uint8_t *);
495 		p += ETHER_HDR_LEN;
496 		ip = (struct ip *)p;
497 	}
498 	offset = (ip->ip_hl << 2) + ETHER_HDR_LEN;
499 
500  sendit:
501 	offset2 = m->m_pkthdr.csum_data;
502 	*cflags = offset << GEM_TD_CXSUM_STARTSHFT;
503 	*cflags |= ((offset + offset2) << GEM_TD_CXSUM_STUFFSHFT);
504 	*cflags |= GEM_TD_CXSUM_ENABLE;
505 }
506 
507 static __inline void
508 gem_rxcksum(struct mbuf *m, uint64_t flags)
509 {
510 	struct ether_header *eh;
511 	struct ip *ip;
512 	struct udphdr *uh;
513 	uint16_t *opts;
514 	int32_t hlen, len, pktlen;
515 	uint32_t temp32;
516 	uint16_t cksum;
517 
518 	pktlen = m->m_pkthdr.len;
519 	if (pktlen < sizeof(struct ether_header) + sizeof(struct ip))
520 		return;
521 	eh = mtod(m, struct ether_header *);
522 	if (eh->ether_type != htons(ETHERTYPE_IP))
523 		return;
524 	ip = (struct ip *)(eh + 1);
525 	if (ip->ip_v != IPVERSION)
526 		return;
527 
528 	hlen = ip->ip_hl << 2;
529 	pktlen -= sizeof(struct ether_header);
530 	if (hlen < sizeof(struct ip))
531 		return;
532 	if (ntohs(ip->ip_len) < hlen)
533 		return;
534 	if (ntohs(ip->ip_len) != pktlen)
535 		return;
536 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK))
537 		return;	/* Cannot handle fragmented packet. */
538 
539 	switch (ip->ip_p) {
540 	case IPPROTO_TCP:
541 		if (pktlen < (hlen + sizeof(struct tcphdr)))
542 			return;
543 		break;
544 	case IPPROTO_UDP:
545 		if (pktlen < (hlen + sizeof(struct udphdr)))
546 			return;
547 		uh = (struct udphdr *)((uint8_t *)ip + hlen);
548 		if (uh->uh_sum == 0)
549 			return; /* no checksum */
550 		break;
551 	default:
552 		return;
553 	}
554 
555 	cksum = ~(flags & GEM_RD_CHECKSUM);
556 	/* checksum fixup for IP options */
557 	len = hlen - sizeof(struct ip);
558 	if (len > 0) {
559 		opts = (uint16_t *)(ip + 1);
560 		for (; len > 0; len -= sizeof(uint16_t), opts++) {
561 			temp32 = cksum - *opts;
562 			temp32 = (temp32 >> 16) + (temp32 & 65535);
563 			cksum = temp32 & 65535;
564 		}
565 	}
566 	m->m_pkthdr.csum_flags |= CSUM_DATA_VALID;
567 	m->m_pkthdr.csum_data = cksum;
568 }
569 
570 static void
571 gem_cddma_callback(void *xsc, bus_dma_segment_t *segs, int nsegs, int error)
572 {
573 	struct gem_softc *sc = xsc;
574 
575 	if (error != 0)
576 		return;
577 	if (nsegs != 1)
578 		panic("%s: bad control buffer segment count", __func__);
579 	sc->sc_cddma = segs[0].ds_addr;
580 }
581 
582 static void
583 gem_tick(void *arg)
584 {
585 	struct gem_softc *sc = arg;
586 	struct ifnet *ifp;
587 
588 	GEM_LOCK_ASSERT(sc, MA_OWNED);
589 
590 	ifp = sc->sc_ifp;
591 	/*
592 	 * Unload collision counters.
593 	 */
594 	ifp->if_collisions +=
595 	    bus_read_4(sc->sc_res[0], GEM_MAC_NORM_COLL_CNT) +
596 	    bus_read_4(sc->sc_res[0], GEM_MAC_FIRST_COLL_CNT) +
597 	    bus_read_4(sc->sc_res[0], GEM_MAC_EXCESS_COLL_CNT) +
598 	    bus_read_4(sc->sc_res[0], GEM_MAC_LATE_COLL_CNT);
599 
600 	/*
601 	 * then clear the hardware counters.
602 	 */
603 	bus_write_4(sc->sc_res[0], GEM_MAC_NORM_COLL_CNT, 0);
604 	bus_write_4(sc->sc_res[0], GEM_MAC_FIRST_COLL_CNT, 0);
605 	bus_write_4(sc->sc_res[0], GEM_MAC_EXCESS_COLL_CNT, 0);
606 	bus_write_4(sc->sc_res[0], GEM_MAC_LATE_COLL_CNT, 0);
607 
608 	mii_tick(sc->sc_mii);
609 
610 	if (gem_watchdog(sc) == EJUSTRETURN)
611 		return;
612 
613 	callout_reset(&sc->sc_tick_ch, hz, gem_tick, sc);
614 }
615 
616 static int
617 gem_bitwait(struct gem_softc *sc, bus_addr_t r, uint32_t clr, uint32_t set)
618 {
619 	int i;
620 	uint32_t reg;
621 
622 	for (i = TRIES; i--; DELAY(100)) {
623 		reg = bus_read_4(sc->sc_res[0], r);
624 		if ((reg & clr) == 0 && (reg & set) == set)
625 			return (1);
626 	}
627 	return (0);
628 }
629 
630 static void
631 gem_reset(sc)
632 	struct gem_softc *sc;
633 {
634 
635 #ifdef GEM_DEBUG
636 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
637 #endif
638 	gem_reset_rx(sc);
639 	gem_reset_tx(sc);
640 
641 	/* Do a full reset. */
642 	bus_write_4(sc->sc_res[0], GEM_RESET, GEM_RESET_RX | GEM_RESET_TX);
643 	bus_barrier(sc->sc_res[0], GEM_RESET, 4, BUS_SPACE_BARRIER_WRITE);
644 	if (!gem_bitwait(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX, 0))
645 		device_printf(sc->sc_dev, "cannot reset device\n");
646 }
647 
648 static void
649 gem_rxdrain(struct gem_softc *sc)
650 {
651 	struct gem_rxsoft *rxs;
652 	int i;
653 
654 	for (i = 0; i < GEM_NRXDESC; i++) {
655 		rxs = &sc->sc_rxsoft[i];
656 		if (rxs->rxs_mbuf != NULL) {
657 			bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
658 			    BUS_DMASYNC_POSTREAD);
659 			bus_dmamap_unload(sc->sc_rdmatag, rxs->rxs_dmamap);
660 			m_freem(rxs->rxs_mbuf);
661 			rxs->rxs_mbuf = NULL;
662 		}
663 	}
664 }
665 
666 static void
667 gem_stop(struct ifnet *ifp, int disable)
668 {
669 	struct gem_softc *sc = ifp->if_softc;
670 	struct gem_txsoft *txs;
671 
672 #ifdef GEM_DEBUG
673 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
674 #endif
675 
676 	callout_stop(&sc->sc_tick_ch);
677 #ifdef GEM_RINT_TIMEOUT
678 	callout_stop(&sc->sc_rx_ch);
679 #endif
680 
681 	/* XXX should we reset these instead? */
682 	gem_disable_tx(sc);
683 	gem_disable_rx(sc);
684 
685 	/*
686 	 * Release any queued transmit buffers.
687 	 */
688 	while ((txs = STAILQ_FIRST(&sc->sc_txdirtyq)) != NULL) {
689 		STAILQ_REMOVE_HEAD(&sc->sc_txdirtyq, txs_q);
690 		if (txs->txs_ndescs != 0) {
691 			bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
692 			    BUS_DMASYNC_POSTWRITE);
693 			bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
694 			if (txs->txs_mbuf != NULL) {
695 				m_freem(txs->txs_mbuf);
696 				txs->txs_mbuf = NULL;
697 			}
698 		}
699 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
700 	}
701 
702 	if (disable)
703 		gem_rxdrain(sc);
704 
705 	/*
706 	 * Mark the interface down and cancel the watchdog timer.
707 	 */
708 	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
709 	sc->sc_flags &= ~GEM_LINK;
710 	sc->sc_wdog_timer = 0;
711 }
712 
713 static int
714 gem_reset_rx(struct gem_softc *sc)
715 {
716 
717 	/*
718 	 * Resetting while DMA is in progress can cause a bus hang, so we
719 	 * disable DMA first.
720 	 */
721 	gem_disable_rx(sc);
722 	bus_write_4(sc->sc_res[0], GEM_RX_CONFIG, 0);
723 	bus_barrier(sc->sc_res[0], GEM_RX_CONFIG, 4, BUS_SPACE_BARRIER_WRITE);
724 	if (!gem_bitwait(sc, GEM_RX_CONFIG, GEM_RX_CONFIG_RXDMA_EN, 0))
725 		device_printf(sc->sc_dev, "cannot disable RX DMA\n");
726 
727 	/* Finally, reset the ERX */
728 	bus_write_4(sc->sc_res[0], GEM_RESET, GEM_RESET_RX);
729 	bus_barrier(sc->sc_res[0], GEM_RESET, 4, BUS_SPACE_BARRIER_WRITE);
730 	if (!gem_bitwait(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX, 0)) {
731 		device_printf(sc->sc_dev, "cannot reset receiver\n");
732 		return (1);
733 	}
734 	return (0);
735 }
736 
737 /*
738  * Reset the receiver DMA engine.
739  *
740  * Intended to be used in case of GEM_INTR_RX_TAG_ERR, GEM_MAC_RX_OVERFLOW
741  * etc in order to reset the receiver DMA engine only and not do a full
742  * reset which amongst others also downs the link and clears the FIFOs.
743  */
744 static void
745 gem_reset_rxdma(struct gem_softc *sc)
746 {
747 	int i;
748 
749 	if (gem_reset_rx(sc) != 0)
750 		return (gem_init_locked(sc));
751 	for (i = 0; i < GEM_NRXDESC; i++)
752 		if (sc->sc_rxsoft[i].rxs_mbuf != NULL)
753 			GEM_UPDATE_RXDESC(sc, i);
754 	sc->sc_rxptr = 0;
755 	GEM_CDSYNC(sc, BUS_DMASYNC_PREWRITE);
756 	GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD);
757 
758 	/* NOTE: we use only 32-bit DMA addresses here. */
759 	bus_write_4(sc->sc_res[0], GEM_RX_RING_PTR_HI, 0);
760 	bus_write_4(sc->sc_res[0], GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
761 	bus_write_4(sc->sc_res[0], GEM_RX_KICK, GEM_NRXDESC - 4);
762 	bus_write_4(sc->sc_res[0], GEM_RX_CONFIG,
763 	    gem_ringsize(GEM_NRXDESC /* XXX */) |
764 	    ((ETHER_HDR_LEN + sizeof(struct ip)) <<
765 	    GEM_RX_CONFIG_CXM_START_SHFT) |
766 	    (GEM_THRSH_1024 << GEM_RX_CONFIG_FIFO_THRS_SHIFT) |
767 	    (2 << GEM_RX_CONFIG_FBOFF_SHFT));
768 	bus_write_4(sc->sc_res[0], GEM_RX_BLANKING,
769 	    (6 << GEM_RX_BLANKING_TIME_SHIFT) | 6);
770 	bus_write_4(sc->sc_res[0], GEM_RX_PAUSE_THRESH,
771 	    (3 * sc->sc_rxfifosize / 256) |
772 	    ((sc->sc_rxfifosize / 256) << 12));
773 	bus_write_4(sc->sc_res[0], GEM_RX_CONFIG,
774 	    bus_read_4(sc->sc_res[0], GEM_RX_CONFIG) |
775 	    GEM_RX_CONFIG_RXDMA_EN);
776 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_MASK,
777 	    GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT);
778 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CONFIG,
779 	    bus_read_4(sc->sc_res[0], GEM_MAC_RX_CONFIG) |
780 	    GEM_MAC_RX_ENABLE);
781 }
782 
783 static int
784 gem_reset_tx(struct gem_softc *sc)
785 {
786 
787 	/*
788 	 * Resetting while DMA is in progress can cause a bus hang, so we
789 	 * disable DMA first.
790 	 */
791 	gem_disable_tx(sc);
792 	bus_write_4(sc->sc_res[0], GEM_TX_CONFIG, 0);
793 	bus_barrier(sc->sc_res[0], GEM_TX_CONFIG, 4, BUS_SPACE_BARRIER_WRITE);
794 	if (!gem_bitwait(sc, GEM_TX_CONFIG, GEM_TX_CONFIG_TXDMA_EN, 0))
795 		device_printf(sc->sc_dev, "cannot disable TX DMA\n");
796 
797 	/* Finally, reset the ETX */
798 	bus_write_4(sc->sc_res[0], GEM_RESET, GEM_RESET_TX);
799 	bus_barrier(sc->sc_res[0], GEM_RESET, 4, BUS_SPACE_BARRIER_WRITE);
800 	if (!gem_bitwait(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX, 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 	uint32_t cfg;
811 
812 	cfg = bus_read_4(sc->sc_res[0], GEM_MAC_RX_CONFIG);
813 	cfg &= ~GEM_MAC_RX_ENABLE;
814 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CONFIG, cfg);
815 	bus_barrier(sc->sc_res[0], GEM_MAC_RX_CONFIG, 4,
816 	    BUS_SPACE_BARRIER_WRITE);
817 	return (gem_bitwait(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0));
818 }
819 
820 /*
821  * disable transmitter.
822  */
823 static int
824 gem_disable_tx(struct gem_softc *sc)
825 {
826 	uint32_t cfg;
827 
828 	cfg = bus_read_4(sc->sc_res[0], GEM_MAC_TX_CONFIG);
829 	cfg &= ~GEM_MAC_TX_ENABLE;
830 	bus_write_4(sc->sc_res[0], GEM_MAC_TX_CONFIG, cfg);
831 	bus_barrier(sc->sc_res[0], GEM_MAC_TX_CONFIG, 4,
832 	    BUS_SPACE_BARRIER_WRITE);
833 	return (gem_bitwait(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0));
834 }
835 
836 static int
837 gem_meminit(sc)
838 	struct gem_softc *sc;
839 {
840 	struct gem_rxsoft *rxs;
841 	int error, i;
842 
843 	/*
844 	 * Initialize the transmit descriptor ring.
845 	 */
846 	for (i = 0; i < GEM_NTXDESC; i++) {
847 		sc->sc_txdescs[i].gd_flags = 0;
848 		sc->sc_txdescs[i].gd_addr = 0;
849 	}
850 	sc->sc_txfree = GEM_MAXTXFREE;
851 	sc->sc_txnext = 0;
852 	sc->sc_txwin = 0;
853 
854 	/*
855 	 * Initialize the receive descriptor and receive job
856 	 * descriptor rings.
857 	 */
858 	for (i = 0; i < GEM_NRXDESC; i++) {
859 		rxs = &sc->sc_rxsoft[i];
860 		if (rxs->rxs_mbuf == NULL) {
861 			if ((error = gem_add_rxbuf(sc, i)) != 0) {
862 				device_printf(sc->sc_dev,
863 				    "unable to allocate or map RX buffer %d, "
864 				    "error = %d\n", i, error);
865 				/*
866 				 * XXX we should attempt to run with fewer
867 				 * receive buffers instead of just failing.
868 				 */
869 				gem_rxdrain(sc);
870 				return (1);
871 			}
872 		} else
873 			GEM_INIT_RXDESC(sc, i);
874 	}
875 	sc->sc_rxptr = 0;
876 	GEM_CDSYNC(sc, BUS_DMASYNC_PREWRITE);
877 	GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD);
878 
879 	return (0);
880 }
881 
882 static u_int
883 gem_ringsize(u_int sz)
884 {
885 
886 	switch (sz) {
887 	case 32:
888 		return (GEM_RING_SZ_32);
889 	case 64:
890 		return (GEM_RING_SZ_64);
891 	case 128:
892 		return (GEM_RING_SZ_128);
893 	case 256:
894 		return (GEM_RING_SZ_256);
895 	case 512:
896 		return (GEM_RING_SZ_512);
897 	case 1024:
898 		return (GEM_RING_SZ_1024);
899 	case 2048:
900 		return (GEM_RING_SZ_2048);
901 	case 4096:
902 		return (GEM_RING_SZ_4096);
903 	case 8192:
904 		return (GEM_RING_SZ_8192);
905 	default:
906 		printf("%s: invalid ring size %d\n", __func__, sz);
907 		return (GEM_RING_SZ_32);
908 	}
909 }
910 
911 static void
912 gem_init(void *xsc)
913 {
914 	struct gem_softc *sc = xsc;
915 
916 	GEM_LOCK(sc);
917 	gem_init_locked(sc);
918 	GEM_UNLOCK(sc);
919 }
920 
921 /*
922  * Initialization of interface; set up initialization block
923  * and transmit/receive descriptor rings.
924  */
925 static void
926 gem_init_locked(struct gem_softc *sc)
927 {
928 	struct ifnet *ifp = sc->sc_ifp;
929 	uint32_t v;
930 
931 	GEM_LOCK_ASSERT(sc, MA_OWNED);
932 
933 #ifdef GEM_DEBUG
934 	CTR2(KTR_GEM, "%s: %s: calling stop", device_get_name(sc->sc_dev),
935 	    __func__);
936 #endif
937 	/*
938 	 * Initialization sequence.  The numbered steps below correspond
939 	 * to the sequence outlined in section 6.3.5.1 in the Ethernet
940 	 * Channel Engine manual (part of the PCIO manual).
941 	 * See also the STP2002-STQ document from Sun Microsystems.
942 	 */
943 
944 	/* step 1 & 2.  Reset the Ethernet Channel. */
945 	gem_stop(sc->sc_ifp, 0);
946 	gem_reset(sc);
947 #ifdef GEM_DEBUG
948 	CTR2(KTR_GEM, "%s: %s: restarting", device_get_name(sc->sc_dev),
949 	    __func__);
950 #endif
951 
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 	bus_write_4(sc->sc_res[0], GEM_TX_RING_PTR_HI, 0);
968 	bus_write_4(sc->sc_res[0], GEM_TX_RING_PTR_LO, GEM_CDTXADDR(sc, 0));
969 
970 	bus_write_4(sc->sc_res[0], GEM_RX_RING_PTR_HI, 0);
971 	bus_write_4(sc->sc_res[0], 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 	bus_write_4(sc->sc_res[0], GEM_INTMASK,
979 	    ~(GEM_INTR_TX_INTME | GEM_INTR_TX_EMPTY | GEM_INTR_RX_DONE |
980 	    GEM_INTR_RX_NOBUF | GEM_INTR_RX_TAG_ERR | GEM_INTR_PERR |
981 	    GEM_INTR_BERR
982 #ifdef GEM_DEBUG
983 	    | GEM_INTR_PCS | GEM_INTR_MIF
984 #endif
985 	    ));
986 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_MASK,
987 	    GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT);
988 	bus_write_4(sc->sc_res[0], GEM_MAC_TX_MASK,
989 	    GEM_MAC_TX_XMIT_DONE | GEM_MAC_TX_DEFER_EXP);
990 #ifdef GEM_DEBUG
991 	bus_write_4(sc->sc_res[0], GEM_MAC_CONTROL_MASK,
992 	    ~(GEM_MAC_PAUSED | GEM_MAC_PAUSE | GEM_MAC_RESUME));
993 #else
994 	bus_write_4(sc->sc_res[0], GEM_MAC_CONTROL_MASK,
995 	    GEM_MAC_PAUSED | GEM_MAC_PAUSE | GEM_MAC_RESUME);
996 #endif
997 
998 	/* step 9.  ETX Configuration: use mostly default values. */
999 
1000 	/* Enable DMA. */
1001 	v = gem_ringsize(GEM_NTXDESC /* XXX */);
1002 	bus_write_4(sc->sc_res[0], GEM_TX_CONFIG,
1003 	    v | GEM_TX_CONFIG_TXDMA_EN |
1004 	    ((0x400 << 10) & GEM_TX_CONFIG_TXFIFO_TH));
1005 
1006 	/* step 10.  ERX Configuration */
1007 
1008 	/* Encode Receive Descriptor ring size. */
1009 	v = gem_ringsize(GEM_NRXDESC /* XXX */);
1010 	/* RX TCP/UDP checksum offset */
1011 	v |= ((ETHER_HDR_LEN + sizeof(struct ip)) <<
1012 	    GEM_RX_CONFIG_CXM_START_SHFT);
1013 
1014 	/* Enable DMA. */
1015 	bus_write_4(sc->sc_res[0], GEM_RX_CONFIG,
1016 	    v | (GEM_THRSH_1024 << GEM_RX_CONFIG_FIFO_THRS_SHIFT) |
1017 	    (2 << GEM_RX_CONFIG_FBOFF_SHFT) | GEM_RX_CONFIG_RXDMA_EN);
1018 
1019 	bus_write_4(sc->sc_res[0], GEM_RX_BLANKING,
1020 	    (6 << GEM_RX_BLANKING_TIME_SHIFT) | 6);
1021 
1022 	/*
1023 	 * The following value is for an OFF Threshold of about 3/4 full
1024 	 * and an ON Threshold of 1/4 full.
1025 	 */
1026 	bus_write_4(sc->sc_res[0], GEM_RX_PAUSE_THRESH,
1027 	    (3 * sc->sc_rxfifosize / 256) |
1028 	    ((sc->sc_rxfifosize / 256) << 12));
1029 
1030 	/* step 11.  Configure Media. */
1031 
1032 	/* step 12.  RX_MAC Configuration Register */
1033 	v = bus_read_4(sc->sc_res[0], GEM_MAC_RX_CONFIG);
1034 	v |= GEM_MAC_RX_STRIP_CRC;
1035 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CONFIG, 0);
1036 	bus_barrier(sc->sc_res[0], GEM_MAC_RX_CONFIG, 4,
1037 	    BUS_SPACE_BARRIER_WRITE);
1038 	if (!gem_bitwait(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0))
1039 		device_printf(sc->sc_dev, "cannot disable RX MAC\n");
1040 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CONFIG, v);
1041 
1042 	/* step 14.  Issue Transmit Pending command. */
1043 
1044 	/* step 15.  Give the reciever a swift kick. */
1045 	bus_write_4(sc->sc_res[0], GEM_RX_KICK, GEM_NRXDESC - 4);
1046 
1047 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
1048 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1049 	sc->sc_ifflags = ifp->if_flags;
1050 
1051 	sc->sc_flags &= ~GEM_LINK;
1052 	mii_mediachg(sc->sc_mii);
1053 
1054 	/* Start the one second timer. */
1055 	sc->sc_wdog_timer = 0;
1056 	callout_reset(&sc->sc_tick_ch, hz, gem_tick, sc);
1057 }
1058 
1059 static int
1060 gem_load_txmbuf(struct gem_softc *sc, struct mbuf **m_head)
1061 {
1062 	bus_dma_segment_t txsegs[GEM_NTXSEGS];
1063 	struct gem_txsoft *txs;
1064 	struct mbuf *m;
1065 	uint64_t cflags, flags;
1066 	int error, nexttx, nsegs, seg;
1067 
1068 	/* Get a work queue entry. */
1069 	if ((txs = STAILQ_FIRST(&sc->sc_txfreeq)) == NULL) {
1070 		/* Ran out of descriptors. */
1071 		return (ENOBUFS);
1072 	}
1073 	error = bus_dmamap_load_mbuf_sg(sc->sc_tdmatag, txs->txs_dmamap,
1074 	    *m_head, txsegs, &nsegs, BUS_DMA_NOWAIT);
1075 	if (error == EFBIG) {
1076 		m = m_collapse(*m_head, M_DONTWAIT, GEM_NTXSEGS);
1077 		if (m == NULL) {
1078 			m_freem(*m_head);
1079 			*m_head = NULL;
1080 			return (ENOBUFS);
1081 		}
1082 		*m_head = m;
1083 		error = bus_dmamap_load_mbuf_sg(sc->sc_tdmatag,
1084 		    txs->txs_dmamap, *m_head, txsegs, &nsegs,
1085 		    BUS_DMA_NOWAIT);
1086 		if (error != 0) {
1087 			m_freem(*m_head);
1088 			*m_head = NULL;
1089 			return (error);
1090 		}
1091 	} else if (error != 0)
1092 		return (error);
1093 	if (nsegs == 0) {
1094 		m_freem(*m_head);
1095 		*m_head = NULL;
1096 		return (EIO);
1097 	}
1098 
1099 	/*
1100 	 * Ensure we have enough descriptors free to describe
1101 	 * the packet.  Note, we always reserve one descriptor
1102 	 * at the end of the ring as a termination point, in
1103 	 * order to prevent wrap-around.
1104 	 */
1105 	if (nsegs > sc->sc_txfree - 1) {
1106 		txs->txs_ndescs = 0;
1107 		bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
1108 		return (ENOBUFS);
1109 	}
1110 
1111 	flags = cflags = 0;
1112 	if (((*m_head)->m_pkthdr.csum_flags & sc->sc_csum_features) != 0)
1113 		gem_txcksum(sc, *m_head, &cflags);
1114 
1115 	txs->txs_ndescs = nsegs;
1116 	txs->txs_firstdesc = sc->sc_txnext;
1117 	nexttx = txs->txs_firstdesc;
1118 	for (seg = 0; seg < nsegs; seg++, nexttx = GEM_NEXTTX(nexttx)) {
1119 #ifdef GEM_DEBUG
1120 		CTR6(KTR_GEM,
1121 		    "%s: mapping seg %d (txd %d), len %lx, addr %#lx (%#lx)",
1122 		    __func__, seg, nexttx, txsegs[seg].ds_len,
1123 		    txsegs[seg].ds_addr,
1124 		    GEM_DMA_WRITE(sc, txsegs[seg].ds_addr));
1125 #endif
1126 		sc->sc_txdescs[nexttx].gd_addr =
1127 		    GEM_DMA_WRITE(sc, txsegs[seg].ds_addr);
1128 		KASSERT(txsegs[seg].ds_len < GEM_TD_BUFSIZE,
1129 		    ("%s: segment size too large!", __func__));
1130 		flags = txsegs[seg].ds_len & GEM_TD_BUFSIZE;
1131 		sc->sc_txdescs[nexttx].gd_flags =
1132 		    GEM_DMA_WRITE(sc, flags | cflags);
1133 		txs->txs_lastdesc = nexttx;
1134 	}
1135 
1136 	/* Set EOP on the last descriptor. */
1137 #ifdef GEM_DEBUG
1138 	CTR3(KTR_GEM, "%s: end of packet at segment %d, TX %d",
1139 	    __func__, seg, nexttx);
1140 #endif
1141 	sc->sc_txdescs[txs->txs_lastdesc].gd_flags |=
1142 	    GEM_DMA_WRITE(sc, GEM_TD_END_OF_PACKET);
1143 
1144 	/* Lastly set SOP on the first descriptor. */
1145 #ifdef GEM_DEBUG
1146 	CTR3(KTR_GEM, "%s: start of packet at segment %d, TX %d",
1147 	    __func__, seg, nexttx);
1148 #endif
1149 	if (++sc->sc_txwin > GEM_NTXSEGS * 2 / 3) {
1150 		sc->sc_txwin = 0;
1151 		flags |= GEM_TD_INTERRUPT_ME;
1152 		sc->sc_txdescs[txs->txs_firstdesc].gd_flags |=
1153 		    GEM_DMA_WRITE(sc, GEM_TD_INTERRUPT_ME |
1154 		    GEM_TD_START_OF_PACKET);
1155 	} else
1156 		sc->sc_txdescs[txs->txs_firstdesc].gd_flags |=
1157 		    GEM_DMA_WRITE(sc, GEM_TD_START_OF_PACKET);
1158 
1159 	/* Sync the DMA map. */
1160 	bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
1161 	    BUS_DMASYNC_PREWRITE);
1162 
1163 #ifdef GEM_DEBUG
1164 	CTR4(KTR_GEM, "%s: setting firstdesc=%d, lastdesc=%d, ndescs=%d",
1165 	    __func__, txs->txs_firstdesc, txs->txs_lastdesc,
1166 	    txs->txs_ndescs);
1167 #endif
1168 	STAILQ_REMOVE_HEAD(&sc->sc_txfreeq, txs_q);
1169 	STAILQ_INSERT_TAIL(&sc->sc_txdirtyq, txs, txs_q);
1170 	txs->txs_mbuf = *m_head;
1171 
1172 	sc->sc_txnext = GEM_NEXTTX(txs->txs_lastdesc);
1173 	sc->sc_txfree -= txs->txs_ndescs;
1174 
1175 	return (0);
1176 }
1177 
1178 static void
1179 gem_init_regs(struct gem_softc *sc)
1180 {
1181 	const u_char *laddr = IF_LLADDR(sc->sc_ifp);
1182 
1183 	/* These registers are not cleared on reset. */
1184 	if ((sc->sc_flags & GEM_INITED) == 0) {
1185 		/* magic values */
1186 		bus_write_4(sc->sc_res[0], GEM_MAC_IPG0, 0);
1187 		bus_write_4(sc->sc_res[0], GEM_MAC_IPG1, 8);
1188 		bus_write_4(sc->sc_res[0], GEM_MAC_IPG2, 4);
1189 
1190 		bus_write_4(sc->sc_res[0], GEM_MAC_MAC_MIN_FRAME,
1191 		    ETHER_MIN_LEN);
1192 		/* max frame and max burst size */
1193 		bus_write_4(sc->sc_res[0], GEM_MAC_MAC_MAX_FRAME,
1194 		    (ETHER_MAX_LEN + ETHER_VLAN_ENCAP_LEN) | (0x2000 << 16));
1195 
1196 		bus_write_4(sc->sc_res[0], GEM_MAC_PREAMBLE_LEN, 0x7);
1197 		bus_write_4(sc->sc_res[0], GEM_MAC_JAM_SIZE, 0x4);
1198 		bus_write_4(sc->sc_res[0], GEM_MAC_ATTEMPT_LIMIT, 0x10);
1199 		/* dunno... */
1200 		bus_write_4(sc->sc_res[0], GEM_MAC_CONTROL_TYPE, 0x8088);
1201 		bus_write_4(sc->sc_res[0], GEM_MAC_RANDOM_SEED,
1202 		    ((laddr[5] << 8) | laddr[4]) & 0x3ff);
1203 
1204 		/* secondary MAC address: 0:0:0:0:0:0 */
1205 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR3, 0);
1206 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR4, 0);
1207 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR5, 0);
1208 
1209 		/* MAC control address: 01:80:c2:00:00:01 */
1210 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR6, 0x0001);
1211 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR7, 0xc200);
1212 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR8, 0x0180);
1213 
1214 		/* MAC filter address: 0:0:0:0:0:0 */
1215 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR_FILTER0, 0);
1216 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR_FILTER1, 0);
1217 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR_FILTER2, 0);
1218 
1219 		bus_write_4(sc->sc_res[0], GEM_MAC_ADR_FLT_MASK1_2, 0);
1220 		bus_write_4(sc->sc_res[0], GEM_MAC_ADR_FLT_MASK0, 0);
1221 
1222 		sc->sc_flags |= GEM_INITED;
1223 	}
1224 
1225 	/* Counters need to be zeroed. */
1226 	bus_write_4(sc->sc_res[0], GEM_MAC_NORM_COLL_CNT, 0);
1227 	bus_write_4(sc->sc_res[0], GEM_MAC_FIRST_COLL_CNT, 0);
1228 	bus_write_4(sc->sc_res[0], GEM_MAC_EXCESS_COLL_CNT, 0);
1229 	bus_write_4(sc->sc_res[0], GEM_MAC_LATE_COLL_CNT, 0);
1230 	bus_write_4(sc->sc_res[0], GEM_MAC_DEFER_TMR_CNT, 0);
1231 	bus_write_4(sc->sc_res[0], GEM_MAC_PEAK_ATTEMPTS, 0);
1232 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_FRAME_COUNT, 0);
1233 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_LEN_ERR_CNT, 0);
1234 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_ALIGN_ERR, 0);
1235 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CRC_ERR_CNT, 0);
1236 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CODE_VIOL, 0);
1237 
1238 	/* Set XOFF PAUSE time. */
1239 	bus_write_4(sc->sc_res[0], GEM_MAC_SEND_PAUSE_CMD, 0x1BF0);
1240 
1241 	/*
1242 	 * Set the internal arbitration to "infinite" bursts of the
1243 	 * maximum length of 31 * 64 bytes so DMA transfers aren't
1244 	 * split up in cache line size chunks.  This greatly improves
1245 	 * especially RX performance.
1246 	 * Enable silicon bug workarounds for the Apple variants.
1247 	 */
1248 	bus_write_4(sc->sc_res[0], GEM_CONFIG,
1249 	    GEM_CONFIG_TXDMA_LIMIT | GEM_CONFIG_RXDMA_LIMIT |
1250 	    GEM_CONFIG_BURST_INF | (GEM_IS_APPLE(sc) ?
1251 	    GEM_CONFIG_RONPAULBIT | GEM_CONFIG_BUG2FIX : 0));
1252 
1253 	/* Set the station address. */
1254 	bus_write_4(sc->sc_res[0], GEM_MAC_ADDR0,
1255 	    (laddr[4] << 8) | laddr[5]);
1256 	bus_write_4(sc->sc_res[0], GEM_MAC_ADDR1,
1257 	    (laddr[2] << 8) | laddr[3]);
1258 	bus_write_4(sc->sc_res[0], GEM_MAC_ADDR2,
1259 	    (laddr[0] << 8) | laddr[1]);
1260 
1261 	/* Enable MII outputs. */
1262 	bus_write_4(sc->sc_res[0], GEM_MAC_XIF_CONFIG,
1263 	    GEM_MAC_XIF_TX_MII_ENA);
1264 }
1265 
1266 static void
1267 gem_start(struct ifnet *ifp)
1268 {
1269 	struct gem_softc *sc = ifp->if_softc;
1270 
1271 	GEM_LOCK(sc);
1272 	gem_start_locked(ifp);
1273 	GEM_UNLOCK(sc);
1274 }
1275 
1276 static void
1277 gem_start_locked(struct ifnet *ifp)
1278 {
1279 	struct gem_softc *sc = ifp->if_softc;
1280 	struct mbuf *m;
1281 	int ntx;
1282 
1283 	if ((ifp->if_drv_flags & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
1284 	    IFF_DRV_RUNNING || (sc->sc_flags & GEM_LINK) == 0)
1285 		return;
1286 
1287 #ifdef GEM_DEBUG
1288 	CTR4(KTR_GEM, "%s: %s: txfree %d, txnext %d",
1289 	    device_get_name(sc->sc_dev), __func__, sc->sc_txfree,
1290 	    sc->sc_txnext);
1291 #endif
1292 	ntx = 0;
1293 	for (; !IFQ_DRV_IS_EMPTY(&ifp->if_snd) && sc->sc_txfree > 1;) {
1294 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
1295 		if (m == NULL)
1296 			break;
1297 		if (gem_load_txmbuf(sc, &m) != 0) {
1298 			if (m == NULL)
1299 				break;
1300 			ifp->if_drv_flags |= IFF_DRV_OACTIVE;
1301 			IFQ_DRV_PREPEND(&ifp->if_snd, m);
1302 			break;
1303 		}
1304 		ntx++;
1305 		/* Kick the transmitter. */
1306 #ifdef GEM_DEBUG
1307 		CTR3(KTR_GEM, "%s: %s: kicking TX %d",
1308 		    device_get_name(sc->sc_dev), __func__, sc->sc_txnext);
1309 #endif
1310 		GEM_CDSYNC(sc, BUS_DMASYNC_PREWRITE);
1311 		bus_write_4(sc->sc_res[0], GEM_TX_KICK, sc->sc_txnext);
1312 
1313 		BPF_MTAP(ifp, m);
1314 	}
1315 
1316 	if (ntx > 0) {
1317 #ifdef GEM_DEBUG
1318 		CTR2(KTR_GEM, "%s: packets enqueued, OWN on %d",
1319 		    device_get_name(sc->sc_dev), sc->sc_txnext);
1320 #endif
1321 
1322 		/* Set a watchdog timer in case the chip flakes out. */
1323 		sc->sc_wdog_timer = 5;
1324 #ifdef GEM_DEBUG
1325 		CTR3(KTR_GEM, "%s: %s: watchdog %d",
1326 		    device_get_name(sc->sc_dev), __func__,
1327 		    sc->sc_wdog_timer);
1328 #endif
1329 	}
1330 }
1331 
1332 static void
1333 gem_tint(struct gem_softc *sc)
1334 {
1335 	struct ifnet *ifp = sc->sc_ifp;
1336 	struct gem_txsoft *txs;
1337 	int txlast, progress;
1338 #ifdef GEM_DEBUG
1339 	int i;
1340 
1341 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
1342 #endif
1343 
1344 	/*
1345 	 * Go through our TX list and free mbufs for those
1346 	 * frames that have been transmitted.
1347 	 */
1348 	progress = 0;
1349 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD);
1350 	while ((txs = STAILQ_FIRST(&sc->sc_txdirtyq)) != NULL) {
1351 
1352 #ifdef GEM_DEBUG
1353 		if ((ifp->if_flags & IFF_DEBUG) != 0) {
1354 			printf("    txsoft %p transmit chain:\n", txs);
1355 			for (i = txs->txs_firstdesc;; i = GEM_NEXTTX(i)) {
1356 				printf("descriptor %d: ", i);
1357 				printf("gd_flags: 0x%016llx\t",
1358 				    (long long)GEM_DMA_READ(sc,
1359 				    sc->sc_txdescs[i].gd_flags));
1360 				printf("gd_addr: 0x%016llx\n",
1361 				    (long long)GEM_DMA_READ(sc,
1362 				    sc->sc_txdescs[i].gd_addr));
1363 				if (i == txs->txs_lastdesc)
1364 					break;
1365 			}
1366 		}
1367 #endif
1368 
1369 		/*
1370 		 * In theory, we could harvest some descriptors before
1371 		 * the ring is empty, but that's a bit complicated.
1372 		 *
1373 		 * GEM_TX_COMPLETION points to the last descriptor
1374 		 * processed + 1.
1375 		 */
1376 		txlast = bus_read_4(sc->sc_res[0], GEM_TX_COMPLETION);
1377 #ifdef GEM_DEBUG
1378 		CTR4(KTR_GEM, "%s: txs->txs_firstdesc = %d, "
1379 		    "txs->txs_lastdesc = %d, txlast = %d",
1380 		    __func__, txs->txs_firstdesc, txs->txs_lastdesc, txlast);
1381 #endif
1382 		if (txs->txs_firstdesc <= txs->txs_lastdesc) {
1383 			if ((txlast >= txs->txs_firstdesc) &&
1384 			    (txlast <= txs->txs_lastdesc))
1385 				break;
1386 		} else {
1387 			/* Ick -- this command wraps. */
1388 			if ((txlast >= txs->txs_firstdesc) ||
1389 			    (txlast <= txs->txs_lastdesc))
1390 				break;
1391 		}
1392 
1393 #ifdef GEM_DEBUG
1394 		CTR1(KTR_GEM, "%s: releasing a descriptor", __func__);
1395 #endif
1396 		STAILQ_REMOVE_HEAD(&sc->sc_txdirtyq, txs_q);
1397 
1398 		sc->sc_txfree += txs->txs_ndescs;
1399 
1400 		bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
1401 		    BUS_DMASYNC_POSTWRITE);
1402 		bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
1403 		if (txs->txs_mbuf != NULL) {
1404 			m_freem(txs->txs_mbuf);
1405 			txs->txs_mbuf = NULL;
1406 		}
1407 
1408 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
1409 
1410 		ifp->if_opackets++;
1411 		progress = 1;
1412 	}
1413 
1414 #ifdef GEM_DEBUG
1415 	CTR4(KTR_GEM, "%s: GEM_TX_STATE_MACHINE %x GEM_TX_DATA_PTR %llx "
1416 	    "GEM_TX_COMPLETION %x",
1417 	    __func__, bus_read_4(sc->sc_res[0], GEM_TX_STATE_MACHINE),
1418 	    ((long long)bus_read_4(sc->sc_res[0],
1419 	    GEM_TX_DATA_PTR_HI) << 32) |
1420 	    bus_read_4(sc->sc_res[0], GEM_TX_DATA_PTR_LO),
1421 	    bus_read_4(sc->sc_res[0], GEM_TX_COMPLETION));
1422 #endif
1423 
1424 	if (progress) {
1425 		if (sc->sc_txfree == GEM_NTXDESC - 1)
1426 			sc->sc_txwin = 0;
1427 
1428 		/*
1429 		 * We freed some descriptors, so reset IFF_DRV_OACTIVE
1430 		 * and restart.
1431 		 */
1432 		ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1433 		sc->sc_wdog_timer = STAILQ_EMPTY(&sc->sc_txdirtyq) ? 0 : 5;
1434 
1435 		if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
1436 		    !IFQ_DRV_IS_EMPTY(&ifp->if_snd))
1437 			gem_start_locked(ifp);
1438 	}
1439 
1440 #ifdef GEM_DEBUG
1441 	CTR3(KTR_GEM, "%s: %s: watchdog %d",
1442 	    device_get_name(sc->sc_dev), __func__, sc->sc_wdog_timer);
1443 #endif
1444 }
1445 
1446 #ifdef GEM_RINT_TIMEOUT
1447 static void
1448 gem_rint_timeout(void *arg)
1449 {
1450 	struct gem_softc *sc = arg;
1451 
1452 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1453 	gem_rint(sc);
1454 }
1455 #endif
1456 
1457 static void
1458 gem_rint(struct gem_softc *sc)
1459 {
1460 	struct ifnet *ifp = sc->sc_ifp;
1461 	struct mbuf *m;
1462 	uint64_t rxstat;
1463 	uint32_t rxcomp;
1464 
1465 #ifdef GEM_RINT_TIMEOUT
1466 	callout_stop(&sc->sc_rx_ch);
1467 #endif
1468 #ifdef GEM_DEBUG
1469 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
1470 #endif
1471 
1472 	/*
1473 	 * Read the completion register once.  This limits
1474 	 * how long the following loop can execute.
1475 	 */
1476 	rxcomp = bus_read_4(sc->sc_res[0], GEM_RX_COMPLETION);
1477 
1478 #ifdef GEM_DEBUG
1479 	CTR3(KTR_GEM, "%s: sc->rxptr %d, complete %d",
1480 	    __func__, sc->sc_rxptr, rxcomp);
1481 #endif
1482 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD);
1483 	for (; sc->sc_rxptr != rxcomp;) {
1484 		m = sc->sc_rxsoft[sc->sc_rxptr].rxs_mbuf;
1485 		rxstat = GEM_DMA_READ(sc,
1486 		    sc->sc_rxdescs[sc->sc_rxptr].gd_flags);
1487 
1488 		if (rxstat & GEM_RD_OWN) {
1489 #ifdef GEM_RINT_TIMEOUT
1490 			/*
1491 			 * The descriptor is still marked as owned, although
1492 			 * it is supposed to have completed.  This has been
1493 			 * observed on some machines.  Just exiting here
1494 			 * might leave the packet sitting around until another
1495 			 * one arrives to trigger a new interrupt, which is
1496 			 * generally undesirable, so set up a timeout.
1497 			 */
1498 			callout_reset(&sc->sc_rx_ch, GEM_RXOWN_TICKS,
1499 			    gem_rint_timeout, sc);
1500 #endif
1501 			m = NULL;
1502 			goto kickit;
1503 		}
1504 
1505 		if (rxstat & GEM_RD_BAD_CRC) {
1506 			ifp->if_ierrors++;
1507 			device_printf(sc->sc_dev, "receive error: CRC error\n");
1508 			GEM_INIT_RXDESC(sc, sc->sc_rxptr);
1509 			m = NULL;
1510 			goto kickit;
1511 		}
1512 
1513 #ifdef GEM_DEBUG
1514 		if ((ifp->if_flags & IFF_DEBUG) != 0) {
1515 			printf("    rxsoft %p descriptor %d: ",
1516 			    &sc->sc_rxsoft[sc->sc_rxptr], sc->sc_rxptr);
1517 			printf("gd_flags: 0x%016llx\t",
1518 			    (long long)GEM_DMA_READ(sc,
1519 			    sc->sc_rxdescs[sc->sc_rxptr].gd_flags));
1520 			printf("gd_addr: 0x%016llx\n",
1521 			    (long long)GEM_DMA_READ(sc,
1522 			    sc->sc_rxdescs[sc->sc_rxptr].gd_addr));
1523 		}
1524 #endif
1525 
1526 		/*
1527 		 * Allocate a new mbuf cluster.  If that fails, we are
1528 		 * out of memory, and must drop the packet and recycle
1529 		 * the buffer that's already attached to this descriptor.
1530 		 */
1531 		if (gem_add_rxbuf(sc, sc->sc_rxptr) != 0) {
1532 			ifp->if_ierrors++;
1533 			GEM_INIT_RXDESC(sc, sc->sc_rxptr);
1534 			m = NULL;
1535 		}
1536 
1537  kickit:
1538 		/*
1539 		 * Update the RX kick register.  This register has to point
1540 		 * to the descriptor after the last valid one (before the
1541 		 * current batch) and must be incremented in multiples of
1542 		 * 4 (because the DMA engine fetches/updates descriptors
1543 		 * in batches of 4).
1544 		 */
1545 		sc->sc_rxptr = GEM_NEXTRX(sc->sc_rxptr);
1546 		if ((sc->sc_rxptr % 4) == 0) {
1547 			GEM_CDSYNC(sc, BUS_DMASYNC_PREWRITE);
1548 			bus_write_4(sc->sc_res[0], GEM_RX_KICK,
1549 			    (sc->sc_rxptr + GEM_NRXDESC - 4) &
1550 			    GEM_NRXDESC_MASK);
1551 		}
1552 
1553 		if (m == NULL) {
1554 			if (rxstat & GEM_RD_OWN)
1555 				break;
1556 			continue;
1557 		}
1558 
1559 		ifp->if_ipackets++;
1560 		m->m_data += 2; /* We're already off by two */
1561 		m->m_pkthdr.rcvif = ifp;
1562 		m->m_pkthdr.len = m->m_len = GEM_RD_BUFLEN(rxstat);
1563 
1564 		if ((ifp->if_capenable & IFCAP_RXCSUM) != 0)
1565 			gem_rxcksum(m, rxstat);
1566 
1567 		/* Pass it on. */
1568 		GEM_UNLOCK(sc);
1569 		(*ifp->if_input)(ifp, m);
1570 		GEM_LOCK(sc);
1571 	}
1572 
1573 #ifdef GEM_DEBUG
1574 	CTR3(KTR_GEM, "%s: done sc->rxptr %d, complete %d", __func__,
1575 	    sc->sc_rxptr, bus_read_4(sc->sc_res[0], GEM_RX_COMPLETION));
1576 #endif
1577 }
1578 
1579 static int
1580 gem_add_rxbuf(struct gem_softc *sc, int idx)
1581 {
1582 	struct gem_rxsoft *rxs = &sc->sc_rxsoft[idx];
1583 	struct mbuf *m;
1584 	bus_dma_segment_t segs[1];
1585 	int error, nsegs;
1586 
1587 	m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
1588 	if (m == NULL)
1589 		return (ENOBUFS);
1590 	m->m_len = m->m_pkthdr.len = m->m_ext.ext_size;
1591 
1592 #ifdef GEM_DEBUG
1593 	/* Bzero the packet to check DMA. */
1594 	memset(m->m_ext.ext_buf, 0, m->m_ext.ext_size);
1595 #endif
1596 
1597 	if (rxs->rxs_mbuf != NULL) {
1598 		bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
1599 		    BUS_DMASYNC_POSTREAD);
1600 		bus_dmamap_unload(sc->sc_rdmatag, rxs->rxs_dmamap);
1601 	}
1602 
1603 	error = bus_dmamap_load_mbuf_sg(sc->sc_rdmatag, rxs->rxs_dmamap,
1604 	    m, segs, &nsegs, BUS_DMA_NOWAIT);
1605 	KASSERT(nsegs == 1, ("Too many segments returned!"));
1606 	if (error != 0) {
1607 		device_printf(sc->sc_dev,
1608 		    "cannot load RS DMA map %d, error = %d\n", idx, error);
1609 		m_freem(m);
1610 		return (error);
1611 	}
1612 	/* If nsegs is wrong then the stack is corrupt. */
1613 	rxs->rxs_mbuf = m;
1614 	rxs->rxs_paddr = segs[0].ds_addr;
1615 
1616 	bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
1617 	    BUS_DMASYNC_PREREAD);
1618 
1619 	GEM_INIT_RXDESC(sc, idx);
1620 
1621 	return (0);
1622 }
1623 
1624 static void
1625 gem_eint(struct gem_softc *sc, u_int status)
1626 {
1627 
1628 	sc->sc_ifp->if_ierrors++;
1629 	if ((status & GEM_INTR_RX_TAG_ERR) != 0) {
1630 		gem_reset_rxdma(sc);
1631 		return;
1632 	}
1633 
1634 	device_printf(sc->sc_dev, "%s: status=%x\n", __func__, status);
1635 }
1636 
1637 void
1638 gem_intr(void *v)
1639 {
1640 	struct gem_softc *sc = v;
1641 	uint32_t status, status2;
1642 
1643 	GEM_LOCK(sc);
1644 	status = bus_read_4(sc->sc_res[0], GEM_STATUS);
1645 
1646 #ifdef GEM_DEBUG
1647 	CTR4(KTR_GEM, "%s: %s: cplt %x, status %x",
1648 	    device_get_name(sc->sc_dev), __func__, (status >> 19),
1649 	    (u_int)status);
1650 
1651 	/*
1652 	 * PCS interrupts must be cleared, otherwise no traffic is passed!
1653 	 */
1654 	if ((status & GEM_INTR_PCS) != 0) {
1655 		status2 =
1656 		    bus_read_4(sc->sc_res[0], GEM_MII_INTERRUP_STATUS) |
1657 		    bus_read_4(sc->sc_res[0], GEM_MII_INTERRUP_STATUS);
1658 		if ((status2 & GEM_MII_INTERRUP_LINK) != 0)
1659 			device_printf(sc->sc_dev,
1660 			    "%s: PCS link status changed\n", __func__);
1661 	}
1662 	if ((status & GEM_MAC_CONTROL_STATUS) != 0) {
1663 		status2 = bus_read_4(sc->sc_res[0], GEM_MAC_CONTROL_STATUS);
1664 		if ((status2 & GEM_MAC_PAUSED) != 0)
1665 			device_printf(sc->sc_dev,
1666 			    "%s: PAUSE received (PAUSE time %d slots)\n",
1667 			    __func__, GEM_MAC_PAUSE_TIME(status2));
1668 		if ((status2 & GEM_MAC_PAUSE) != 0)
1669 			device_printf(sc->sc_dev,
1670 			    "%s: transited to PAUSE state\n", __func__);
1671 		if ((status2 & GEM_MAC_RESUME) != 0)
1672 			device_printf(sc->sc_dev,
1673 			    "%s: transited to non-PAUSE state\n", __func__);
1674 	}
1675 	if ((status & GEM_INTR_MIF) != 0)
1676 		device_printf(sc->sc_dev, "%s: MIF interrupt\n", __func__);
1677 #endif
1678 
1679 	if ((status &
1680 	    (GEM_INTR_RX_TAG_ERR | GEM_INTR_PERR | GEM_INTR_BERR)) != 0)
1681 		gem_eint(sc, status);
1682 
1683 	if ((status & (GEM_INTR_RX_DONE | GEM_INTR_RX_NOBUF)) != 0)
1684 		gem_rint(sc);
1685 
1686 	if ((status & (GEM_INTR_TX_EMPTY | GEM_INTR_TX_INTME)) != 0)
1687 		gem_tint(sc);
1688 
1689 	if (status & GEM_INTR_TX_MAC) {
1690 		status2 = bus_read_4(sc->sc_res[0], GEM_MAC_TX_STATUS);
1691 		if ((status2 &
1692 		    ~(GEM_MAC_TX_XMIT_DONE | GEM_MAC_TX_DEFER_EXP)) != 0)
1693 			device_printf(sc->sc_dev,
1694 			    "MAC TX fault, status %x\n", status2);
1695 		if ((status2 &
1696 		    (GEM_MAC_TX_UNDERRUN | GEM_MAC_TX_PKT_TOO_LONG)) != 0)
1697 			gem_init_locked(sc);
1698 	}
1699 	if (status & GEM_INTR_RX_MAC) {
1700 		status2 = bus_read_4(sc->sc_res[0], GEM_MAC_RX_STATUS);
1701 		/*
1702 		 * At least with GEM_SUN_GEM and some GEM_SUN_ERI
1703 		 * revisions GEM_MAC_RX_OVERFLOW happen often due to a
1704 		 * silicon bug so handle them silently.  Moreover, it's
1705 		 * likely that the receiver has hung so we reset it.
1706 		 */
1707 		if ((status2 & GEM_MAC_RX_OVERFLOW) != 0) {
1708 			sc->sc_ifp->if_ierrors++;
1709 			gem_reset_rxdma(sc);
1710 		} else if ((status2 &
1711 		    ~(GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT)) != 0)
1712 			device_printf(sc->sc_dev,
1713 			    "MAC RX fault, status %x\n", status2);
1714 	}
1715 	GEM_UNLOCK(sc);
1716 }
1717 
1718 static int
1719 gem_watchdog(struct gem_softc *sc)
1720 {
1721 
1722 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1723 
1724 #ifdef GEM_DEBUG
1725 	CTR4(KTR_GEM,
1726 	    "%s: GEM_RX_CONFIG %x GEM_MAC_RX_STATUS %x GEM_MAC_RX_CONFIG %x",
1727 	    __func__, bus_read_4(sc->sc_res[0], GEM_RX_CONFIG),
1728 	    bus_read_4(sc->sc_res[0], GEM_MAC_RX_STATUS),
1729 	    bus_read_4(sc->sc_res[0], GEM_MAC_RX_CONFIG));
1730 	CTR4(KTR_GEM,
1731 	    "%s: GEM_TX_CONFIG %x GEM_MAC_TX_STATUS %x GEM_MAC_TX_CONFIG %x",
1732 	    __func__, bus_read_4(sc->sc_res[0], GEM_TX_CONFIG),
1733 	    bus_read_4(sc->sc_res[0], GEM_MAC_TX_STATUS),
1734 	    bus_read_4(sc->sc_res[0], GEM_MAC_TX_CONFIG));
1735 #endif
1736 
1737 	if (sc->sc_wdog_timer == 0 || --sc->sc_wdog_timer != 0)
1738 		return (0);
1739 
1740 	if ((sc->sc_flags & GEM_LINK) != 0)
1741 		device_printf(sc->sc_dev, "device timeout\n");
1742 	else if (bootverbose)
1743 		device_printf(sc->sc_dev, "device timeout (no link)\n");
1744 	++sc->sc_ifp->if_oerrors;
1745 
1746 	/* Try to get more packets going. */
1747 	gem_init_locked(sc);
1748 	return (EJUSTRETURN);
1749 }
1750 
1751 static void
1752 gem_mifinit(struct gem_softc *sc)
1753 {
1754 
1755 	/* Configure the MIF in frame mode */
1756 	bus_write_4(sc->sc_res[0], GEM_MIF_CONFIG, bus_read_4(sc->sc_res[0],
1757 	    GEM_MIF_CONFIG) & ~GEM_MIF_CONFIG_BB_ENA);
1758 }
1759 
1760 /*
1761  * MII interface
1762  *
1763  * The GEM MII interface supports at least three different operating modes:
1764  *
1765  * Bitbang mode is implemented using data, clock and output enable registers.
1766  *
1767  * Frame mode is implemented by loading a complete frame into the frame
1768  * register and polling the valid bit for completion.
1769  *
1770  * Polling mode uses the frame register but completion is indicated by
1771  * an interrupt.
1772  *
1773  */
1774 int
1775 gem_mii_readreg(device_t dev, int phy, int reg)
1776 {
1777 	struct gem_softc *sc;
1778 	int n;
1779 	uint32_t v;
1780 
1781 #ifdef GEM_DEBUG_PHY
1782 	printf("%s: phy %d reg %d\n", __func__, phy, reg);
1783 #endif
1784 
1785 	sc = device_get_softc(dev);
1786 	if (sc->sc_phyad != -1 && phy != sc->sc_phyad)
1787 		return (0);
1788 
1789 	if ((sc->sc_flags & GEM_SERDES) != 0) {
1790 		switch (reg) {
1791 		case MII_BMCR:
1792 			reg = GEM_MII_CONTROL;
1793 			break;
1794 		case MII_BMSR:
1795 			reg = GEM_MII_STATUS;
1796 			break;
1797 		case MII_PHYIDR1:
1798 		case MII_PHYIDR2:
1799 			return (0);
1800 		case MII_ANAR:
1801 			reg = GEM_MII_ANAR;
1802 			break;
1803 		case MII_ANLPAR:
1804 			reg = GEM_MII_ANLPAR;
1805 			break;
1806 		case MII_EXTSR:
1807 			return (EXTSR_1000XFDX | EXTSR_1000XHDX);
1808 		default:
1809 			device_printf(sc->sc_dev,
1810 			    "%s: unhandled register %d\n", __func__, reg);
1811 			return (0);
1812 		}
1813 		return (bus_read_4(sc->sc_res[0], reg));
1814 	}
1815 
1816 	/* Construct the frame command. */
1817 	v = GEM_MIF_FRAME_READ |
1818 	    (phy << GEM_MIF_PHY_SHIFT) |
1819 	    (reg << GEM_MIF_REG_SHIFT);
1820 
1821 	bus_write_4(sc->sc_res[0], GEM_MIF_FRAME, v);
1822 	for (n = 0; n < 100; n++) {
1823 		DELAY(1);
1824 		v = bus_read_4(sc->sc_res[0], GEM_MIF_FRAME);
1825 		if (v & GEM_MIF_FRAME_TA0)
1826 			return (v & GEM_MIF_FRAME_DATA);
1827 	}
1828 
1829 	device_printf(sc->sc_dev, "%s: timed out\n", __func__);
1830 	return (0);
1831 }
1832 
1833 int
1834 gem_mii_writereg(device_t dev, int phy, int reg, int val)
1835 {
1836 	struct gem_softc *sc;
1837 	int n;
1838 	uint32_t v;
1839 
1840 #ifdef GEM_DEBUG_PHY
1841 	printf("%s: phy %d reg %d val %x\n", phy, reg, val, __func__);
1842 #endif
1843 
1844 	sc = device_get_softc(dev);
1845 	if (sc->sc_phyad != -1 && phy != sc->sc_phyad)
1846 		return (0);
1847 
1848 	if ((sc->sc_flags & GEM_SERDES) != 0) {
1849 		switch (reg) {
1850 		case MII_BMCR:
1851 			reg = GEM_MII_CONTROL;
1852 			break;
1853 		case MII_BMSR:
1854 			reg = GEM_MII_STATUS;
1855 			break;
1856 		case MII_ANAR:
1857 			bus_write_4(sc->sc_res[0], GEM_MII_CONFIG, 0);
1858 			bus_barrier(sc->sc_res[0], GEM_MII_CONFIG, 4,
1859 			    BUS_SPACE_BARRIER_WRITE);
1860 			bus_write_4(sc->sc_res[0], GEM_MII_ANAR, val);
1861 			bus_write_4(sc->sc_res[0], GEM_MII_SLINK_CONTROL,
1862 			    GEM_MII_SLINK_LOOPBACK | GEM_MII_SLINK_EN_SYNC_D);
1863 			bus_write_4(sc->sc_res[0], GEM_MII_CONFIG,
1864 			    GEM_MII_CONFIG_ENABLE);
1865 			return (0);
1866 		case MII_ANLPAR:
1867 			reg = GEM_MII_ANLPAR;
1868 			break;
1869 		default:
1870 			device_printf(sc->sc_dev,
1871 			    "%s: unhandled register %d\n", __func__, reg);
1872 			return (0);
1873 		}
1874 		bus_write_4(sc->sc_res[0], reg, val);
1875 		return (0);
1876 	}
1877 
1878 	/* Construct the frame command. */
1879 	v = GEM_MIF_FRAME_WRITE |
1880 	    (phy << GEM_MIF_PHY_SHIFT) |
1881 	    (reg << GEM_MIF_REG_SHIFT) |
1882 	    (val & GEM_MIF_FRAME_DATA);
1883 
1884 	bus_write_4(sc->sc_res[0], GEM_MIF_FRAME, v);
1885 	for (n = 0; n < 100; n++) {
1886 		DELAY(1);
1887 		v = bus_read_4(sc->sc_res[0], GEM_MIF_FRAME);
1888 		if (v & GEM_MIF_FRAME_TA0)
1889 			return (1);
1890 	}
1891 
1892 	device_printf(sc->sc_dev, "%s: timed out\n", __func__);
1893 	return (0);
1894 }
1895 
1896 void
1897 gem_mii_statchg(device_t dev)
1898 {
1899 	struct gem_softc *sc;
1900 	int gigabit;
1901 	uint32_t rxcfg, txcfg, v;
1902 
1903 	sc = device_get_softc(dev);
1904 
1905 #ifdef GEM_DEBUG
1906 	if ((sc->sc_ifp->if_flags & IFF_DEBUG) != 0)
1907 		device_printf(sc->sc_dev, "%s: status change: PHY = %d\n",
1908 		    __func__, sc->sc_phyad);
1909 #endif
1910 
1911 	if ((sc->sc_mii->mii_media_status & IFM_ACTIVE) != 0 &&
1912 	    IFM_SUBTYPE(sc->sc_mii->mii_media_active) != IFM_NONE)
1913 		sc->sc_flags |= GEM_LINK;
1914 	else
1915 		sc->sc_flags &= ~GEM_LINK;
1916 
1917 	switch (IFM_SUBTYPE(sc->sc_mii->mii_media_active)) {
1918 	case IFM_1000_SX:
1919 	case IFM_1000_LX:
1920 	case IFM_1000_CX:
1921 	case IFM_1000_T:
1922 		gigabit = 1;
1923 		break;
1924 	default:
1925 		gigabit = 0;
1926 	}
1927 
1928 	/*
1929 	 * The configuration done here corresponds to the steps F) and
1930 	 * G) and as far as enabling of RX and TX MAC goes also step H)
1931 	 * of the initialization sequence outlined in section 3.2.1 of
1932 	 * the GEM Gigabit Ethernet ASIC Specification.
1933 	 */
1934 
1935 	rxcfg = bus_read_4(sc->sc_res[0], GEM_MAC_RX_CONFIG);
1936 	rxcfg &= ~(GEM_MAC_RX_CARR_EXTEND | GEM_MAC_RX_ENABLE);
1937 	txcfg = GEM_MAC_TX_ENA_IPG0 | GEM_MAC_TX_NGU | GEM_MAC_TX_NGU_LIMIT;
1938 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) != 0)
1939 		txcfg |= GEM_MAC_TX_IGN_CARRIER | GEM_MAC_TX_IGN_COLLIS;
1940 	else if (gigabit != 0) {
1941 		rxcfg |= GEM_MAC_RX_CARR_EXTEND;
1942 		txcfg |= GEM_MAC_TX_CARR_EXTEND;
1943 	}
1944 	bus_write_4(sc->sc_res[0], GEM_MAC_TX_CONFIG, 0);
1945 	bus_barrier(sc->sc_res[0], GEM_MAC_TX_CONFIG, 4,
1946 	    BUS_SPACE_BARRIER_WRITE);
1947 	if (!gem_bitwait(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0))
1948 		device_printf(sc->sc_dev, "cannot disable TX MAC\n");
1949 	bus_write_4(sc->sc_res[0], GEM_MAC_TX_CONFIG, txcfg);
1950 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CONFIG, 0);
1951 	bus_barrier(sc->sc_res[0], GEM_MAC_RX_CONFIG, 4,
1952 	    BUS_SPACE_BARRIER_WRITE);
1953 	if (!gem_bitwait(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0))
1954 		device_printf(sc->sc_dev, "cannot disable RX MAC\n");
1955 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CONFIG, rxcfg);
1956 
1957 	v = bus_read_4(sc->sc_res[0], GEM_MAC_CONTROL_CONFIG) &
1958 	    ~(GEM_MAC_CC_RX_PAUSE | GEM_MAC_CC_TX_PAUSE);
1959 #ifdef notyet
1960 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
1961 	    IFM_ETH_RXPAUSE) != 0)
1962 		v |= GEM_MAC_CC_RX_PAUSE;
1963 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
1964 	    IFM_ETH_TXPAUSE) != 0)
1965 		v |= GEM_MAC_CC_TX_PAUSE;
1966 #endif
1967 	bus_write_4(sc->sc_res[0], GEM_MAC_CONTROL_CONFIG, v);
1968 
1969 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) == 0 &&
1970 	    gigabit != 0)
1971 		bus_write_4(sc->sc_res[0], GEM_MAC_SLOT_TIME,
1972 		    GEM_MAC_SLOT_TIME_CARR_EXTEND);
1973 	else
1974 		bus_write_4(sc->sc_res[0], GEM_MAC_SLOT_TIME,
1975 		    GEM_MAC_SLOT_TIME_NORMAL);
1976 
1977 	/* XIF Configuration */
1978 	v = GEM_MAC_XIF_LINK_LED;
1979 	v |= GEM_MAC_XIF_TX_MII_ENA;
1980 	if ((sc->sc_flags & GEM_SERDES) == 0) {
1981 		if ((bus_read_4(sc->sc_res[0], GEM_MIF_CONFIG) &
1982 		    GEM_MIF_CONFIG_PHY_SEL) != 0 &&
1983 		    (IFM_OPTIONS(sc->sc_mii->mii_media_active) &
1984 		    IFM_FDX) == 0)
1985 			/* External MII needs echo disable if half duplex. */
1986 			v |= GEM_MAC_XIF_ECHO_DISABL;
1987 		else
1988 			/*
1989 			 * Internal MII needs buffer enable.
1990 			 * XXX buffer enable makes only sense for an
1991 			 * external PHY.
1992 			 */
1993 			v |= GEM_MAC_XIF_MII_BUF_ENA;
1994 	}
1995 	if (gigabit != 0)
1996 		v |= GEM_MAC_XIF_GMII_MODE;
1997 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) != 0)
1998 		v |= GEM_MAC_XIF_FDPLX_LED;
1999 	bus_write_4(sc->sc_res[0], GEM_MAC_XIF_CONFIG, v);
2000 
2001 	if ((sc->sc_ifp->if_drv_flags & IFF_DRV_RUNNING) != 0 &&
2002 	    (sc->sc_flags & GEM_LINK) != 0) {
2003 		bus_write_4(sc->sc_res[0], GEM_MAC_TX_CONFIG,
2004 		    txcfg | GEM_MAC_TX_ENABLE);
2005 		bus_write_4(sc->sc_res[0], GEM_MAC_RX_CONFIG,
2006 		    rxcfg | GEM_MAC_RX_ENABLE);
2007 	}
2008 }
2009 
2010 int
2011 gem_mediachange(struct ifnet *ifp)
2012 {
2013 	struct gem_softc *sc = ifp->if_softc;
2014 	int error;
2015 
2016 	/* XXX add support for serial media. */
2017 
2018 	GEM_LOCK(sc);
2019 	error = mii_mediachg(sc->sc_mii);
2020 	GEM_UNLOCK(sc);
2021 	return (error);
2022 }
2023 
2024 void
2025 gem_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
2026 {
2027 	struct gem_softc *sc = ifp->if_softc;
2028 
2029 	GEM_LOCK(sc);
2030 	if ((ifp->if_flags & IFF_UP) == 0) {
2031 		GEM_UNLOCK(sc);
2032 		return;
2033 	}
2034 
2035 	mii_pollstat(sc->sc_mii);
2036 	ifmr->ifm_active = sc->sc_mii->mii_media_active;
2037 	ifmr->ifm_status = sc->sc_mii->mii_media_status;
2038 	GEM_UNLOCK(sc);
2039 }
2040 
2041 static int
2042 gem_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
2043 {
2044 	struct gem_softc *sc = ifp->if_softc;
2045 	struct ifreq *ifr = (struct ifreq *)data;
2046 	int error;
2047 
2048 	error = 0;
2049 	switch (cmd) {
2050 	case SIOCSIFFLAGS:
2051 		GEM_LOCK(sc);
2052 		if ((ifp->if_flags & IFF_UP) != 0) {
2053 			if ((ifp->if_drv_flags & IFF_DRV_RUNNING) != 0 &&
2054 			    ((ifp->if_flags ^ sc->sc_ifflags) &
2055 			    (IFF_ALLMULTI | IFF_PROMISC)) != 0)
2056 				gem_setladrf(sc);
2057 			else
2058 				gem_init_locked(sc);
2059 		} else if ((ifp->if_drv_flags & IFF_DRV_RUNNING) != 0)
2060 			gem_stop(ifp, 0);
2061 		if ((ifp->if_flags & IFF_LINK0) != 0)
2062 			sc->sc_csum_features |= CSUM_UDP;
2063 		else
2064 			sc->sc_csum_features &= ~CSUM_UDP;
2065 		if ((ifp->if_capenable & IFCAP_TXCSUM) != 0)
2066 			ifp->if_hwassist = sc->sc_csum_features;
2067 		sc->sc_ifflags = ifp->if_flags;
2068 		GEM_UNLOCK(sc);
2069 		break;
2070 	case SIOCADDMULTI:
2071 	case SIOCDELMULTI:
2072 		GEM_LOCK(sc);
2073 		gem_setladrf(sc);
2074 		GEM_UNLOCK(sc);
2075 		break;
2076 	case SIOCGIFMEDIA:
2077 	case SIOCSIFMEDIA:
2078 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_mii->mii_media, cmd);
2079 		break;
2080 	case SIOCSIFCAP:
2081 		GEM_LOCK(sc);
2082 		ifp->if_capenable = ifr->ifr_reqcap;
2083 		if ((ifp->if_capenable & IFCAP_TXCSUM) != 0)
2084 			ifp->if_hwassist = sc->sc_csum_features;
2085 		else
2086 			ifp->if_hwassist = 0;
2087 		GEM_UNLOCK(sc);
2088 		break;
2089 	default:
2090 		error = ether_ioctl(ifp, cmd, data);
2091 		break;
2092 	}
2093 
2094 	return (error);
2095 }
2096 
2097 static void
2098 gem_setladrf(struct gem_softc *sc)
2099 {
2100 	struct ifnet *ifp = sc->sc_ifp;
2101 	struct ifmultiaddr *inm;
2102 	int i;
2103 	uint32_t hash[16];
2104 	uint32_t crc, v;
2105 
2106 	GEM_LOCK_ASSERT(sc, MA_OWNED);
2107 
2108 	/* Get the current RX configuration. */
2109 	v = bus_read_4(sc->sc_res[0], GEM_MAC_RX_CONFIG);
2110 
2111 	/*
2112 	 * Turn off promiscuous mode, promiscuous group mode (all multicast),
2113 	 * and hash filter.  Depending on the case, the right bit will be
2114 	 * enabled.
2115 	 */
2116 	v &= ~(GEM_MAC_RX_PROMISCUOUS | GEM_MAC_RX_HASH_FILTER |
2117 	    GEM_MAC_RX_PROMISC_GRP);
2118 
2119 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CONFIG, v);
2120 	bus_barrier(sc->sc_res[0], GEM_MAC_RX_CONFIG, 4,
2121 	    BUS_SPACE_BARRIER_WRITE);
2122 	if (!gem_bitwait(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_HASH_FILTER, 0))
2123 		device_printf(sc->sc_dev, "cannot disable RX hash filter\n");
2124 
2125 	if ((ifp->if_flags & IFF_PROMISC) != 0) {
2126 		v |= GEM_MAC_RX_PROMISCUOUS;
2127 		goto chipit;
2128 	}
2129 	if ((ifp->if_flags & IFF_ALLMULTI) != 0) {
2130 		v |= GEM_MAC_RX_PROMISC_GRP;
2131 		goto chipit;
2132 	}
2133 
2134 	/*
2135 	 * Set up multicast address filter by passing all multicast
2136 	 * addresses through a crc generator, and then using the high
2137 	 * order 8 bits as an index into the 256 bit logical address
2138 	 * filter.  The high order 4 bits selects the word, while the
2139 	 * other 4 bits select the bit within the word (where bit 0
2140 	 * is the MSB).
2141 	 */
2142 
2143 	/* Clear the hash table. */
2144 	memset(hash, 0, sizeof(hash));
2145 
2146 	IF_ADDR_LOCK(ifp);
2147 	TAILQ_FOREACH(inm, &ifp->if_multiaddrs, ifma_link) {
2148 		if (inm->ifma_addr->sa_family != AF_LINK)
2149 			continue;
2150 		crc = ether_crc32_le(LLADDR((struct sockaddr_dl *)
2151 		    inm->ifma_addr), ETHER_ADDR_LEN);
2152 
2153 		/* We just want the 8 most significant bits. */
2154 		crc >>= 24;
2155 
2156 		/* Set the corresponding bit in the filter. */
2157 		hash[crc >> 4] |= 1 << (15 - (crc & 15));
2158 	}
2159 	IF_ADDR_UNLOCK(ifp);
2160 
2161 	v |= GEM_MAC_RX_HASH_FILTER;
2162 
2163 	/* Now load the hash table into the chip (if we are using it). */
2164 	for (i = 0; i < 16; i++)
2165 		bus_write_4(sc->sc_res[0],
2166 		    GEM_MAC_HASH0 + i * (GEM_MAC_HASH1 - GEM_MAC_HASH0),
2167 		    hash[i]);
2168 
2169  chipit:
2170 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CONFIG, v);
2171 }
2172