xref: /freebsd/sys/dev/gem/if_gem.c (revision 7937bfbc0ca53fe7cdd0d54414f9296e273a518e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (C) 2001 Eduardo Horvath.
5  * Copyright (c) 2001-2003 Thomas Moestl
6  * Copyright (c) 2007 Marius Strobl <marius@FreeBSD.org>
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR  ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR  BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  *	from: NetBSD: gem.c,v 1.21 2002/06/01 23:50:58 lukem Exp
31  */
32 
33 #include <sys/cdefs.h>
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_var.h>
65 #include <net/if_arp.h>
66 #include <net/if_dl.h>
67 #include <net/if_media.h>
68 #include <net/if_types.h>
69 #include <net/if_vlan_var.h>
70 
71 #include <netinet/in.h>
72 #include <netinet/in_systm.h>
73 #include <netinet/ip.h>
74 #include <netinet/tcp.h>
75 #include <netinet/udp.h>
76 
77 #include <machine/bus.h>
78 
79 #include <dev/mii/mii.h>
80 #include <dev/mii/miivar.h>
81 
82 #include <dev/gem/if_gemreg.h>
83 #include <dev/gem/if_gemvar.h>
84 
85 CTASSERT(powerof2(GEM_NRXDESC) && GEM_NRXDESC >= 32 && GEM_NRXDESC <= 8192);
86 CTASSERT(powerof2(GEM_NTXDESC) && GEM_NTXDESC >= 32 && GEM_NTXDESC <= 8192);
87 
88 #define	GEM_TRIES	10000
89 
90 /*
91  * The hardware supports basic TCP/UDP checksum offloading.  However,
92  * the hardware doesn't compensate the checksum for UDP datagram which
93  * can yield to 0x0.  As a safe guard, UDP checksum offload is disabled
94  * by default.  It can be reactivated by setting special link option
95  * link0 with ifconfig(8).
96  */
97 #define	GEM_CSUM_FEATURES	(CSUM_TCP)
98 
99 static int	gem_add_rxbuf(struct gem_softc *sc, int idx);
100 static int	gem_bitwait(struct gem_softc *sc, bus_addr_t r, uint32_t clr,
101 		    uint32_t set);
102 static void	gem_cddma_callback(void *xsc, bus_dma_segment_t *segs,
103 		    int nsegs, int error);
104 static int	gem_disable_rx(struct gem_softc *sc);
105 static int	gem_disable_tx(struct gem_softc *sc);
106 static void	gem_eint(struct gem_softc *sc, u_int status);
107 static void	gem_init(void *xsc);
108 static void	gem_init_locked(struct gem_softc *sc);
109 static void	gem_init_regs(struct gem_softc *sc);
110 static int	gem_ioctl(if_t ifp, u_long cmd, caddr_t data);
111 static int	gem_load_txmbuf(struct gem_softc *sc, struct mbuf **m_head);
112 static int	gem_meminit(struct gem_softc *sc);
113 static void	gem_mifinit(struct gem_softc *sc);
114 static void	gem_reset(struct gem_softc *sc);
115 static int	gem_reset_rx(struct gem_softc *sc);
116 static void	gem_reset_rxdma(struct gem_softc *sc);
117 static int	gem_reset_tx(struct gem_softc *sc);
118 static u_int	gem_ringsize(u_int sz);
119 static void	gem_rint(struct gem_softc *sc);
120 #ifdef GEM_RINT_TIMEOUT
121 static void	gem_rint_timeout(void *arg);
122 #endif
123 static inline void gem_rxcksum(struct mbuf *m, uint64_t flags);
124 static void	gem_rxdrain(struct gem_softc *sc);
125 static void	gem_setladrf(struct gem_softc *sc);
126 static void	gem_start(if_t ifp);
127 static void	gem_start_locked(if_t ifp);
128 static void	gem_stop(if_t ifp, int disable);
129 static void	gem_tick(void *arg);
130 static void	gem_tint(struct gem_softc *sc);
131 static inline void gem_txkick(struct gem_softc *sc);
132 static int	gem_watchdog(struct gem_softc *sc);
133 
134 DRIVER_MODULE(miibus, gem, miibus_driver, 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 int
143 gem_attach(struct gem_softc *sc)
144 {
145 	struct gem_txsoft *txs;
146 	if_t ifp;
147 	int error, i, phy;
148 	uint32_t v;
149 
150 	if (bootverbose)
151 		device_printf(sc->sc_dev, "flags=0x%x\n", sc->sc_flags);
152 
153 	/* Set up ifnet structure. */
154 	ifp = sc->sc_ifp = if_alloc(IFT_ETHER);
155 	sc->sc_csum_features = GEM_CSUM_FEATURES;
156 	if_setsoftc(ifp, sc);
157 	if_initname(ifp, device_get_name(sc->sc_dev),
158 	    device_get_unit(sc->sc_dev));
159 	if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
160 	if_setstartfn(ifp, gem_start);
161 	if_setioctlfn(ifp, gem_ioctl);
162 	if_setinitfn(ifp, gem_init);
163 	if_setsendqlen(ifp, GEM_TXQUEUELEN);
164 	if_setsendqready(ifp);
165 
166 	callout_init_mtx(&sc->sc_tick_ch, &sc->sc_mtx, 0);
167 #ifdef GEM_RINT_TIMEOUT
168 	callout_init_mtx(&sc->sc_rx_ch, &sc->sc_mtx, 0);
169 #endif
170 
171 	/* Make sure the chip is stopped. */
172 	gem_reset(sc);
173 
174 	error = bus_dma_tag_create(bus_get_dma_tag(sc->sc_dev), 1, 0,
175 	    BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
176 	    BUS_SPACE_MAXSIZE_32BIT, 0, BUS_SPACE_MAXSIZE_32BIT, 0, NULL,
177 	    NULL, &sc->sc_pdmatag);
178 	if (error != 0)
179 		goto fail_ifnet;
180 
181 	error = bus_dma_tag_create(sc->sc_pdmatag, 1, 0,
182 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL, MCLBYTES,
183 	    1, MCLBYTES, BUS_DMA_ALLOCNOW, NULL, NULL, &sc->sc_rdmatag);
184 	if (error != 0)
185 		goto fail_ptag;
186 
187 	error = bus_dma_tag_create(sc->sc_pdmatag, 1, 0,
188 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
189 	    MCLBYTES * GEM_NTXSEGS, GEM_NTXSEGS, MCLBYTES,
190 	    BUS_DMA_ALLOCNOW, NULL, NULL, &sc->sc_tdmatag);
191 	if (error != 0)
192 		goto fail_rtag;
193 
194 	error = bus_dma_tag_create(sc->sc_pdmatag, PAGE_SIZE, 0,
195 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
196 	    sizeof(struct gem_control_data), 1,
197 	    sizeof(struct gem_control_data), 0,
198 	    NULL, NULL, &sc->sc_cdmatag);
199 	if (error != 0)
200 		goto fail_ttag;
201 
202 	/*
203 	 * Allocate the control data structures, create and load the
204 	 * DMA map for it.
205 	 */
206 	if ((error = bus_dmamem_alloc(sc->sc_cdmatag,
207 	    (void **)&sc->sc_control_data,
208 	    BUS_DMA_WAITOK | BUS_DMA_COHERENT | BUS_DMA_ZERO,
209 	    &sc->sc_cddmamap)) != 0) {
210 		device_printf(sc->sc_dev,
211 		    "unable to allocate control data, error = %d\n", error);
212 		goto fail_ctag;
213 	}
214 
215 	sc->sc_cddma = 0;
216 	if ((error = bus_dmamap_load(sc->sc_cdmatag, sc->sc_cddmamap,
217 	    sc->sc_control_data, sizeof(struct gem_control_data),
218 	    gem_cddma_callback, sc, 0)) != 0 || sc->sc_cddma == 0) {
219 		device_printf(sc->sc_dev,
220 		    "unable to load control data DMA map, error = %d\n",
221 		    error);
222 		goto fail_cmem;
223 	}
224 
225 	/*
226 	 * Initialize the transmit job descriptors.
227 	 */
228 	STAILQ_INIT(&sc->sc_txfreeq);
229 	STAILQ_INIT(&sc->sc_txdirtyq);
230 
231 	/*
232 	 * Create the transmit buffer DMA maps.
233 	 */
234 	error = ENOMEM;
235 	for (i = 0; i < GEM_TXQUEUELEN; i++) {
236 		txs = &sc->sc_txsoft[i];
237 		txs->txs_mbuf = NULL;
238 		txs->txs_ndescs = 0;
239 		if ((error = bus_dmamap_create(sc->sc_tdmatag, 0,
240 		    &txs->txs_dmamap)) != 0) {
241 			device_printf(sc->sc_dev,
242 			    "unable to create TX DMA map %d, error = %d\n",
243 			    i, error);
244 			goto fail_txd;
245 		}
246 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
247 	}
248 
249 	/*
250 	 * Create the receive buffer DMA maps.
251 	 */
252 	for (i = 0; i < GEM_NRXDESC; i++) {
253 		if ((error = bus_dmamap_create(sc->sc_rdmatag, 0,
254 		    &sc->sc_rxsoft[i].rxs_dmamap)) != 0) {
255 			device_printf(sc->sc_dev,
256 			    "unable to create RX DMA map %d, error = %d\n",
257 			    i, error);
258 			goto fail_rxd;
259 		}
260 		sc->sc_rxsoft[i].rxs_mbuf = NULL;
261 	}
262 
263 	/* Bypass probing PHYs if we already know for sure to use a SERDES. */
264 	if ((sc->sc_flags & GEM_SERDES) != 0)
265 		goto serdes;
266 
267 	GEM_WRITE_4(sc, GEM_MII_DATAPATH_MODE, GEM_MII_DATAPATH_MII);
268 	GEM_BARRIER(sc, GEM_MII_DATAPATH_MODE, 4,
269 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
270 
271 	gem_mifinit(sc);
272 
273 	/*
274 	 * Look for an external PHY.
275 	 */
276 	error = ENXIO;
277 	v = GEM_READ_4(sc, GEM_MIF_CONFIG);
278 	if ((v & GEM_MIF_CONFIG_MDI1) != 0) {
279 		v |= GEM_MIF_CONFIG_PHY_SEL;
280 		GEM_WRITE_4(sc, GEM_MIF_CONFIG, v);
281 		GEM_BARRIER(sc, GEM_MIF_CONFIG, 4,
282 		    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
283 		error = mii_attach(sc->sc_dev, &sc->sc_miibus, ifp,
284 		    gem_mediachange, gem_mediastatus, BMSR_DEFCAPMASK,
285 		    MII_PHY_ANY, MII_OFFSET_ANY, MIIF_DOPAUSE);
286 	}
287 
288 	/*
289 	 * Fall back on an internal PHY if no external PHY was found.
290 	 * Note that with Apple (K2) GMACs GEM_MIF_CONFIG_MDI0 can't be
291 	 * trusted when the firmware has powered down the chip.
292 	 */
293 	if (error != 0 &&
294 	    ((v & GEM_MIF_CONFIG_MDI0) != 0 || GEM_IS_APPLE(sc))) {
295 		v &= ~GEM_MIF_CONFIG_PHY_SEL;
296 		GEM_WRITE_4(sc, GEM_MIF_CONFIG, v);
297 		GEM_BARRIER(sc, GEM_MIF_CONFIG, 4,
298 		    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
299 		switch (sc->sc_variant) {
300 		case GEM_APPLE_K2_GMAC:
301 			phy = GEM_PHYAD_INTERNAL;
302 			break;
303 		case GEM_APPLE_GMAC:
304 			phy = GEM_PHYAD_EXTERNAL;
305 			break;
306 		default:
307 			phy = MII_PHY_ANY;
308 			break;
309 		}
310 		error = mii_attach(sc->sc_dev, &sc->sc_miibus, ifp,
311 		    gem_mediachange, gem_mediastatus, BMSR_DEFCAPMASK, phy,
312 		    MII_OFFSET_ANY, MIIF_DOPAUSE);
313 	}
314 
315 	/*
316 	 * Try the external PCS SERDES if we didn't find any PHYs.
317 	 */
318 	if (error != 0 && sc->sc_variant == GEM_SUN_GEM) {
319  serdes:
320 		GEM_WRITE_4(sc, GEM_MII_DATAPATH_MODE,
321 		    GEM_MII_DATAPATH_SERDES);
322 		GEM_BARRIER(sc, GEM_MII_DATAPATH_MODE, 4,
323 		    BUS_SPACE_BARRIER_WRITE);
324 		GEM_WRITE_4(sc, GEM_MII_SLINK_CONTROL,
325 		    GEM_MII_SLINK_LOOPBACK | GEM_MII_SLINK_EN_SYNC_D);
326 		GEM_BARRIER(sc, GEM_MII_SLINK_CONTROL, 4,
327 		    BUS_SPACE_BARRIER_WRITE);
328 		GEM_WRITE_4(sc, GEM_MII_CONFIG, GEM_MII_CONFIG_ENABLE);
329 		GEM_BARRIER(sc, GEM_MII_CONFIG, 4,
330 		    BUS_SPACE_BARRIER_WRITE);
331 		sc->sc_flags |= GEM_SERDES;
332 		error = mii_attach(sc->sc_dev, &sc->sc_miibus, ifp,
333 		    gem_mediachange, gem_mediastatus, BMSR_DEFCAPMASK,
334 		    GEM_PHYAD_EXTERNAL, MII_OFFSET_ANY, MIIF_DOPAUSE);
335 	}
336 	if (error != 0) {
337 		device_printf(sc->sc_dev, "attaching PHYs failed\n");
338 		goto fail_rxd;
339 	}
340 	sc->sc_mii = device_get_softc(sc->sc_miibus);
341 
342 	/*
343 	 * From this point forward, the attachment cannot fail.  A failure
344 	 * before this point releases all resources that may have been
345 	 * allocated.
346 	 */
347 
348 	/* Get RX FIFO size. */
349 	sc->sc_rxfifosize = 64 *
350 	    GEM_READ_4(sc, GEM_RX_FIFO_SIZE);
351 
352 	/* Get TX FIFO size. */
353 	v = GEM_READ_4(sc, GEM_TX_FIFO_SIZE);
354 	device_printf(sc->sc_dev, "%ukB RX FIFO, %ukB TX FIFO\n",
355 	    sc->sc_rxfifosize / 1024, v / 16);
356 
357 	/* Attach the interface. */
358 	ether_ifattach(ifp, sc->sc_enaddr);
359 
360 	/*
361 	 * Tell the upper layer(s) we support long frames/checksum offloads.
362 	 */
363 	if_setifheaderlen(ifp, sizeof(struct ether_vlan_header));
364 	if_setcapabilitiesbit(ifp, IFCAP_VLAN_MTU | IFCAP_HWCSUM, 0);
365 	if_sethwassistbits(ifp, sc->sc_csum_features, 0);
366 	if_setcapenablebit(ifp, IFCAP_VLAN_MTU | IFCAP_HWCSUM, 0);
367 
368 	return (0);
369 
370 	/*
371 	 * Free any resources we've allocated during the failed attach
372 	 * attempt.  Do this in reverse order and fall through.
373 	 */
374  fail_rxd:
375 	for (i = 0; i < GEM_NRXDESC; i++)
376 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
377 			bus_dmamap_destroy(sc->sc_rdmatag,
378 			    sc->sc_rxsoft[i].rxs_dmamap);
379  fail_txd:
380 	for (i = 0; i < GEM_TXQUEUELEN; i++)
381 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
382 			bus_dmamap_destroy(sc->sc_tdmatag,
383 			    sc->sc_txsoft[i].txs_dmamap);
384 	bus_dmamap_unload(sc->sc_cdmatag, sc->sc_cddmamap);
385  fail_cmem:
386 	bus_dmamem_free(sc->sc_cdmatag, sc->sc_control_data,
387 	    sc->sc_cddmamap);
388  fail_ctag:
389 	bus_dma_tag_destroy(sc->sc_cdmatag);
390  fail_ttag:
391 	bus_dma_tag_destroy(sc->sc_tdmatag);
392  fail_rtag:
393 	bus_dma_tag_destroy(sc->sc_rdmatag);
394  fail_ptag:
395 	bus_dma_tag_destroy(sc->sc_pdmatag);
396  fail_ifnet:
397 	if_free(ifp);
398 	return (error);
399 }
400 
401 void
402 gem_detach(struct gem_softc *sc)
403 {
404 	if_t ifp = sc->sc_ifp;
405 	int i;
406 
407 	ether_ifdetach(ifp);
408 	GEM_LOCK(sc);
409 	gem_stop(ifp, 1);
410 	GEM_UNLOCK(sc);
411 	callout_drain(&sc->sc_tick_ch);
412 #ifdef GEM_RINT_TIMEOUT
413 	callout_drain(&sc->sc_rx_ch);
414 #endif
415 	if_free(ifp);
416 	device_delete_child(sc->sc_dev, sc->sc_miibus);
417 
418 	for (i = 0; i < GEM_NRXDESC; i++)
419 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
420 			bus_dmamap_destroy(sc->sc_rdmatag,
421 			    sc->sc_rxsoft[i].rxs_dmamap);
422 	for (i = 0; i < GEM_TXQUEUELEN; i++)
423 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
424 			bus_dmamap_destroy(sc->sc_tdmatag,
425 			    sc->sc_txsoft[i].txs_dmamap);
426 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
427 	bus_dmamap_unload(sc->sc_cdmatag, sc->sc_cddmamap);
428 	bus_dmamem_free(sc->sc_cdmatag, sc->sc_control_data,
429 	    sc->sc_cddmamap);
430 	bus_dma_tag_destroy(sc->sc_cdmatag);
431 	bus_dma_tag_destroy(sc->sc_tdmatag);
432 	bus_dma_tag_destroy(sc->sc_rdmatag);
433 	bus_dma_tag_destroy(sc->sc_pdmatag);
434 }
435 
436 void
437 gem_suspend(struct gem_softc *sc)
438 {
439 	if_t ifp = sc->sc_ifp;
440 
441 	GEM_LOCK(sc);
442 	gem_stop(ifp, 0);
443 	GEM_UNLOCK(sc);
444 }
445 
446 void
447 gem_resume(struct gem_softc *sc)
448 {
449 	if_t ifp = sc->sc_ifp;
450 
451 	GEM_LOCK(sc);
452 	/*
453 	 * On resume all registers have to be initialized again like
454 	 * after power-on.
455 	 */
456 	sc->sc_flags &= ~GEM_INITED;
457 	if (if_getflags(ifp) & IFF_UP)
458 		gem_init_locked(sc);
459 	GEM_UNLOCK(sc);
460 }
461 
462 static inline void
463 gem_rxcksum(struct mbuf *m, uint64_t flags)
464 {
465 	struct ether_header *eh;
466 	struct ip *ip;
467 	struct udphdr *uh;
468 	uint16_t *opts;
469 	int32_t hlen, len, pktlen;
470 	uint32_t temp32;
471 	uint16_t cksum;
472 
473 	pktlen = m->m_pkthdr.len;
474 	if (pktlen < sizeof(struct ether_header) + sizeof(struct ip))
475 		return;
476 	eh = mtod(m, struct ether_header *);
477 	if (eh->ether_type != htons(ETHERTYPE_IP))
478 		return;
479 	ip = (struct ip *)(eh + 1);
480 	if (ip->ip_v != IPVERSION)
481 		return;
482 
483 	hlen = ip->ip_hl << 2;
484 	pktlen -= sizeof(struct ether_header);
485 	if (hlen < sizeof(struct ip))
486 		return;
487 	if (ntohs(ip->ip_len) < hlen)
488 		return;
489 	if (ntohs(ip->ip_len) != pktlen)
490 		return;
491 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK))
492 		return;	/* Cannot handle fragmented packet. */
493 
494 	switch (ip->ip_p) {
495 	case IPPROTO_TCP:
496 		if (pktlen < (hlen + sizeof(struct tcphdr)))
497 			return;
498 		break;
499 	case IPPROTO_UDP:
500 		if (pktlen < (hlen + sizeof(struct udphdr)))
501 			return;
502 		uh = (struct udphdr *)((uint8_t *)ip + hlen);
503 		if (uh->uh_sum == 0)
504 			return; /* no checksum */
505 		break;
506 	default:
507 		return;
508 	}
509 
510 	cksum = ~(flags & GEM_RD_CHECKSUM);
511 	/* checksum fixup for IP options */
512 	len = hlen - sizeof(struct ip);
513 	if (len > 0) {
514 		opts = (uint16_t *)(ip + 1);
515 		for (; len > 0; len -= sizeof(uint16_t), opts++) {
516 			temp32 = cksum - *opts;
517 			temp32 = (temp32 >> 16) + (temp32 & 65535);
518 			cksum = temp32 & 65535;
519 		}
520 	}
521 	m->m_pkthdr.csum_flags |= CSUM_DATA_VALID;
522 	m->m_pkthdr.csum_data = cksum;
523 }
524 
525 static void
526 gem_cddma_callback(void *xsc, bus_dma_segment_t *segs, int nsegs, int error)
527 {
528 	struct gem_softc *sc = xsc;
529 
530 	if (error != 0)
531 		return;
532 	if (nsegs != 1)
533 		panic("%s: bad control buffer segment count", __func__);
534 	sc->sc_cddma = segs[0].ds_addr;
535 }
536 
537 static void
538 gem_tick(void *arg)
539 {
540 	struct gem_softc *sc = arg;
541 	if_t ifp = sc->sc_ifp;
542 	uint32_t v;
543 
544 	GEM_LOCK_ASSERT(sc, MA_OWNED);
545 
546 	/*
547 	 * Unload collision and error counters.
548 	 */
549 	if_inc_counter(ifp, IFCOUNTER_COLLISIONS,
550 	    GEM_READ_4(sc, GEM_MAC_NORM_COLL_CNT) +
551 	    GEM_READ_4(sc, GEM_MAC_FIRST_COLL_CNT));
552 	v = GEM_READ_4(sc, GEM_MAC_EXCESS_COLL_CNT) +
553 	    GEM_READ_4(sc, GEM_MAC_LATE_COLL_CNT);
554 	if_inc_counter(ifp, IFCOUNTER_COLLISIONS, v);
555 	if_inc_counter(ifp, IFCOUNTER_OERRORS, v);
556 	if_inc_counter(ifp, IFCOUNTER_IERRORS,
557 	    GEM_READ_4(sc, GEM_MAC_RX_LEN_ERR_CNT) +
558 	    GEM_READ_4(sc, GEM_MAC_RX_ALIGN_ERR) +
559 	    GEM_READ_4(sc, GEM_MAC_RX_CRC_ERR_CNT) +
560 	    GEM_READ_4(sc, GEM_MAC_RX_CODE_VIOL));
561 
562 	/*
563 	 * Then clear the hardware counters.
564 	 */
565 	GEM_WRITE_4(sc, GEM_MAC_NORM_COLL_CNT, 0);
566 	GEM_WRITE_4(sc, GEM_MAC_FIRST_COLL_CNT, 0);
567 	GEM_WRITE_4(sc, GEM_MAC_EXCESS_COLL_CNT, 0);
568 	GEM_WRITE_4(sc, GEM_MAC_LATE_COLL_CNT, 0);
569 	GEM_WRITE_4(sc, GEM_MAC_RX_LEN_ERR_CNT, 0);
570 	GEM_WRITE_4(sc, GEM_MAC_RX_ALIGN_ERR, 0);
571 	GEM_WRITE_4(sc, GEM_MAC_RX_CRC_ERR_CNT, 0);
572 	GEM_WRITE_4(sc, GEM_MAC_RX_CODE_VIOL, 0);
573 
574 	mii_tick(sc->sc_mii);
575 
576 	if (gem_watchdog(sc) == EJUSTRETURN)
577 		return;
578 
579 	callout_reset(&sc->sc_tick_ch, hz, gem_tick, sc);
580 }
581 
582 static int
583 gem_bitwait(struct gem_softc *sc, bus_addr_t r, uint32_t clr, uint32_t set)
584 {
585 	int i;
586 	uint32_t reg;
587 
588 	for (i = GEM_TRIES; i--; DELAY(100)) {
589 		reg = GEM_READ_4(sc, r);
590 		if ((reg & clr) == 0 && (reg & set) == set)
591 			return (1);
592 	}
593 	return (0);
594 }
595 
596 static void
597 gem_reset(struct gem_softc *sc)
598 {
599 
600 #ifdef GEM_DEBUG
601 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
602 #endif
603 	gem_reset_rx(sc);
604 	gem_reset_tx(sc);
605 
606 	/* Do a full reset. */
607 	GEM_WRITE_4(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX);
608 	GEM_BARRIER(sc, GEM_RESET, 4,
609 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
610 	if (!gem_bitwait(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX, 0))
611 		device_printf(sc->sc_dev, "cannot reset device\n");
612 }
613 
614 static void
615 gem_rxdrain(struct gem_softc *sc)
616 {
617 	struct gem_rxsoft *rxs;
618 	int i;
619 
620 	for (i = 0; i < GEM_NRXDESC; i++) {
621 		rxs = &sc->sc_rxsoft[i];
622 		if (rxs->rxs_mbuf != NULL) {
623 			bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
624 			    BUS_DMASYNC_POSTREAD);
625 			bus_dmamap_unload(sc->sc_rdmatag, rxs->rxs_dmamap);
626 			m_freem(rxs->rxs_mbuf);
627 			rxs->rxs_mbuf = NULL;
628 		}
629 	}
630 }
631 
632 static void
633 gem_stop(if_t ifp, int disable)
634 {
635 	struct gem_softc *sc = if_getsoftc(ifp);
636 	struct gem_txsoft *txs;
637 
638 #ifdef GEM_DEBUG
639 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
640 #endif
641 
642 	callout_stop(&sc->sc_tick_ch);
643 #ifdef GEM_RINT_TIMEOUT
644 	callout_stop(&sc->sc_rx_ch);
645 #endif
646 
647 	gem_reset_tx(sc);
648 	gem_reset_rx(sc);
649 
650 	/*
651 	 * Release any queued transmit buffers.
652 	 */
653 	while ((txs = STAILQ_FIRST(&sc->sc_txdirtyq)) != NULL) {
654 		STAILQ_REMOVE_HEAD(&sc->sc_txdirtyq, txs_q);
655 		if (txs->txs_ndescs != 0) {
656 			bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
657 			    BUS_DMASYNC_POSTWRITE);
658 			bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
659 			if (txs->txs_mbuf != NULL) {
660 				m_freem(txs->txs_mbuf);
661 				txs->txs_mbuf = NULL;
662 			}
663 		}
664 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
665 	}
666 
667 	if (disable)
668 		gem_rxdrain(sc);
669 
670 	/*
671 	 * Mark the interface down and cancel the watchdog timer.
672 	 */
673 	if_setdrvflagbits(ifp, 0, (IFF_DRV_RUNNING | IFF_DRV_OACTIVE));
674 	sc->sc_flags &= ~GEM_LINK;
675 	sc->sc_wdog_timer = 0;
676 }
677 
678 static int
679 gem_reset_rx(struct gem_softc *sc)
680 {
681 
682 	/*
683 	 * Resetting while DMA is in progress can cause a bus hang, so we
684 	 * disable DMA first.
685 	 */
686 	(void)gem_disable_rx(sc);
687 	GEM_WRITE_4(sc, GEM_RX_CONFIG, 0);
688 	GEM_BARRIER(sc, GEM_RX_CONFIG, 4,
689 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
690 	if (!gem_bitwait(sc, GEM_RX_CONFIG, GEM_RX_CONFIG_RXDMA_EN, 0))
691 		device_printf(sc->sc_dev, "cannot disable RX DMA\n");
692 
693 	/* Wait 5ms extra. */
694 	DELAY(5000);
695 
696 	/* Reset the ERX. */
697 	GEM_WRITE_4(sc, GEM_RESET, GEM_RESET_RX);
698 	GEM_BARRIER(sc, GEM_RESET, 4,
699 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
700 	if (!gem_bitwait(sc, GEM_RESET, GEM_RESET_RX, 0)) {
701 		device_printf(sc->sc_dev, "cannot reset receiver\n");
702 		return (1);
703 	}
704 
705 	/* Finally, reset RX MAC. */
706 	GEM_WRITE_4(sc, GEM_MAC_RXRESET, 1);
707 	GEM_BARRIER(sc, GEM_MAC_RXRESET, 4,
708 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
709 	if (!gem_bitwait(sc, GEM_MAC_RXRESET, 1, 0)) {
710 		device_printf(sc->sc_dev, "cannot reset RX MAC\n");
711 		return (1);
712 	}
713 
714 	return (0);
715 }
716 
717 /*
718  * Reset the receiver DMA engine.
719  *
720  * Intended to be used in case of GEM_INTR_RX_TAG_ERR, GEM_MAC_RX_OVERFLOW
721  * etc in order to reset the receiver DMA engine only and not do a full
722  * reset which amongst others also downs the link and clears the FIFOs.
723  */
724 static void
725 gem_reset_rxdma(struct gem_softc *sc)
726 {
727 	int i;
728 
729 	if (gem_reset_rx(sc) != 0) {
730 		if_setdrvflagbits(sc->sc_ifp, 0, IFF_DRV_RUNNING);
731 		return (gem_init_locked(sc));
732 	}
733 	for (i = 0; i < GEM_NRXDESC; i++)
734 		if (sc->sc_rxsoft[i].rxs_mbuf != NULL)
735 			GEM_UPDATE_RXDESC(sc, i);
736 	sc->sc_rxptr = 0;
737 	GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
738 
739 	/* NOTE: we use only 32-bit DMA addresses here. */
740 	GEM_WRITE_4(sc, GEM_RX_RING_PTR_HI, 0);
741 	GEM_WRITE_4(sc, GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
742 	GEM_WRITE_4(sc, GEM_RX_KICK, GEM_NRXDESC - 4);
743 	GEM_WRITE_4(sc, GEM_RX_CONFIG,
744 	    gem_ringsize(GEM_NRXDESC /* XXX */) |
745 	    ((ETHER_HDR_LEN + sizeof(struct ip)) <<
746 	    GEM_RX_CONFIG_CXM_START_SHFT) |
747 	    (GEM_THRSH_1024 << GEM_RX_CONFIG_FIFO_THRS_SHIFT) |
748 	    (ETHER_ALIGN << GEM_RX_CONFIG_FBOFF_SHFT));
749 	GEM_WRITE_4(sc, GEM_RX_BLANKING,
750 	    ((6 * (sc->sc_flags & GEM_PCI66) != 0 ? 2 : 1) <<
751 	    GEM_RX_BLANKING_TIME_SHIFT) | 6);
752 	GEM_WRITE_4(sc, GEM_RX_PAUSE_THRESH,
753 	    (3 * sc->sc_rxfifosize / 256) |
754 	    ((sc->sc_rxfifosize / 256) << 12));
755 	GEM_WRITE_4(sc, GEM_RX_CONFIG,
756 	    GEM_READ_4(sc, GEM_RX_CONFIG) | GEM_RX_CONFIG_RXDMA_EN);
757 	GEM_WRITE_4(sc, GEM_MAC_RX_MASK,
758 	    GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT);
759 	/*
760 	 * Clear the RX filter and reprogram it.  This will also set the
761 	 * current RX MAC configuration and enable it.
762 	 */
763 	gem_setladrf(sc);
764 }
765 
766 static int
767 gem_reset_tx(struct gem_softc *sc)
768 {
769 
770 	/*
771 	 * Resetting while DMA is in progress can cause a bus hang, so we
772 	 * disable DMA first.
773 	 */
774 	(void)gem_disable_tx(sc);
775 	GEM_WRITE_4(sc, GEM_TX_CONFIG, 0);
776 	GEM_BARRIER(sc, GEM_TX_CONFIG, 4,
777 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
778 	if (!gem_bitwait(sc, GEM_TX_CONFIG, GEM_TX_CONFIG_TXDMA_EN, 0))
779 		device_printf(sc->sc_dev, "cannot disable TX DMA\n");
780 
781 	/* Wait 5ms extra. */
782 	DELAY(5000);
783 
784 	/* Finally, reset the ETX. */
785 	GEM_WRITE_4(sc, GEM_RESET, GEM_RESET_TX);
786 	GEM_BARRIER(sc, GEM_RESET, 4,
787 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
788 	if (!gem_bitwait(sc, GEM_RESET, GEM_RESET_TX, 0)) {
789 		device_printf(sc->sc_dev, "cannot reset transmitter\n");
790 		return (1);
791 	}
792 	return (0);
793 }
794 
795 static int
796 gem_disable_rx(struct gem_softc *sc)
797 {
798 
799 	GEM_WRITE_4(sc, GEM_MAC_RX_CONFIG,
800 	    GEM_READ_4(sc, GEM_MAC_RX_CONFIG) & ~GEM_MAC_RX_ENABLE);
801 	GEM_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
802 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
803 	if (gem_bitwait(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0))
804 		return (1);
805 	device_printf(sc->sc_dev, "cannot disable RX MAC\n");
806 	return (0);
807 }
808 
809 static int
810 gem_disable_tx(struct gem_softc *sc)
811 {
812 
813 	GEM_WRITE_4(sc, GEM_MAC_TX_CONFIG,
814 	    GEM_READ_4(sc, GEM_MAC_TX_CONFIG) & ~GEM_MAC_TX_ENABLE);
815 	GEM_BARRIER(sc, GEM_MAC_TX_CONFIG, 4,
816 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
817 	if (gem_bitwait(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0))
818 		return (1);
819 	device_printf(sc->sc_dev, "cannot disable TX MAC\n");
820 	return (0);
821 }
822 
823 static int
824 gem_meminit(struct gem_softc *sc)
825 {
826 	struct gem_rxsoft *rxs;
827 	int error, i;
828 
829 	GEM_LOCK_ASSERT(sc, MA_OWNED);
830 
831 	/*
832 	 * Initialize the transmit descriptor ring.
833 	 */
834 	for (i = 0; i < GEM_NTXDESC; i++) {
835 		sc->sc_txdescs[i].gd_flags = 0;
836 		sc->sc_txdescs[i].gd_addr = 0;
837 	}
838 	sc->sc_txfree = GEM_MAXTXFREE;
839 	sc->sc_txnext = 0;
840 	sc->sc_txwin = 0;
841 
842 	/*
843 	 * Initialize the receive descriptor and receive job
844 	 * descriptor rings.
845 	 */
846 	for (i = 0; i < GEM_NRXDESC; i++) {
847 		rxs = &sc->sc_rxsoft[i];
848 		if (rxs->rxs_mbuf == NULL) {
849 			if ((error = gem_add_rxbuf(sc, i)) != 0) {
850 				device_printf(sc->sc_dev,
851 				    "unable to allocate or map RX buffer %d, "
852 				    "error = %d\n", i, error);
853 				/*
854 				 * XXX we should attempt to run with fewer
855 				 * receive buffers instead of just failing.
856 				 */
857 				gem_rxdrain(sc);
858 				return (1);
859 			}
860 		} else
861 			GEM_INIT_RXDESC(sc, i);
862 	}
863 	sc->sc_rxptr = 0;
864 
865 	GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
866 
867 	return (0);
868 }
869 
870 static u_int
871 gem_ringsize(u_int sz)
872 {
873 
874 	switch (sz) {
875 	case 32:
876 		return (GEM_RING_SZ_32);
877 	case 64:
878 		return (GEM_RING_SZ_64);
879 	case 128:
880 		return (GEM_RING_SZ_128);
881 	case 256:
882 		return (GEM_RING_SZ_256);
883 	case 512:
884 		return (GEM_RING_SZ_512);
885 	case 1024:
886 		return (GEM_RING_SZ_1024);
887 	case 2048:
888 		return (GEM_RING_SZ_2048);
889 	case 4096:
890 		return (GEM_RING_SZ_4096);
891 	case 8192:
892 		return (GEM_RING_SZ_8192);
893 	default:
894 		printf("%s: invalid ring size %d\n", __func__, sz);
895 		return (GEM_RING_SZ_32);
896 	}
897 }
898 
899 static void
900 gem_init(void *xsc)
901 {
902 	struct gem_softc *sc = xsc;
903 
904 	GEM_LOCK(sc);
905 	gem_init_locked(sc);
906 	GEM_UNLOCK(sc);
907 }
908 
909 /*
910  * Initialization of interface; set up initialization block
911  * and transmit/receive descriptor rings.
912  */
913 static void
914 gem_init_locked(struct gem_softc *sc)
915 {
916 	if_t ifp = sc->sc_ifp;
917 	uint32_t v;
918 
919 	GEM_LOCK_ASSERT(sc, MA_OWNED);
920 
921 	if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0)
922 		return;
923 
924 #ifdef GEM_DEBUG
925 	CTR2(KTR_GEM, "%s: %s: calling stop", device_get_name(sc->sc_dev),
926 	    __func__);
927 #endif
928 	/*
929 	 * Initialization sequence.  The numbered steps below correspond
930 	 * to the sequence outlined in section 6.3.5.1 in the Ethernet
931 	 * Channel Engine manual (part of the PCIO manual).
932 	 * See also the STP2002-STQ document from Sun Microsystems.
933 	 */
934 
935 	/* step 1 & 2.  Reset the Ethernet Channel. */
936 	gem_stop(ifp, 0);
937 	gem_reset(sc);
938 #ifdef GEM_DEBUG
939 	CTR2(KTR_GEM, "%s: %s: restarting", device_get_name(sc->sc_dev),
940 	    __func__);
941 #endif
942 
943 	if ((sc->sc_flags & GEM_SERDES) == 0)
944 		/* Re-initialize the MIF. */
945 		gem_mifinit(sc);
946 
947 	/* step 3.  Setup data structures in host memory. */
948 	if (gem_meminit(sc) != 0)
949 		return;
950 
951 	/* step 4.  TX MAC registers & counters */
952 	gem_init_regs(sc);
953 
954 	/* step 5.  RX MAC registers & counters */
955 
956 	/* step 6 & 7.  Program Descriptor Ring Base Addresses. */
957 	/* NOTE: we use only 32-bit DMA addresses here. */
958 	GEM_WRITE_4(sc, GEM_TX_RING_PTR_HI, 0);
959 	GEM_WRITE_4(sc, GEM_TX_RING_PTR_LO, GEM_CDTXADDR(sc, 0));
960 
961 	GEM_WRITE_4(sc, GEM_RX_RING_PTR_HI, 0);
962 	GEM_WRITE_4(sc, GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
963 #ifdef GEM_DEBUG
964 	CTR3(KTR_GEM, "loading RX ring %lx, TX ring %lx, cddma %lx",
965 	    GEM_CDRXADDR(sc, 0), GEM_CDTXADDR(sc, 0), sc->sc_cddma);
966 #endif
967 
968 	/* step 8.  Global Configuration & Interrupt Mask */
969 
970 	/*
971 	 * Set the internal arbitration to "infinite" bursts of the
972 	 * maximum length of 31 * 64 bytes so DMA transfers aren't
973 	 * split up in cache line size chunks.  This greatly improves
974 	 * RX performance.
975 	 * Enable silicon bug workarounds for the Apple variants.
976 	 */
977 	GEM_WRITE_4(sc, GEM_CONFIG,
978 	    GEM_CONFIG_TXDMA_LIMIT | GEM_CONFIG_RXDMA_LIMIT |
979 	    GEM_CONFIG_BURST_INF | (GEM_IS_APPLE(sc) ?
980 	    GEM_CONFIG_RONPAULBIT | GEM_CONFIG_BUG2FIX : 0));
981 
982 	GEM_WRITE_4(sc, GEM_INTMASK,
983 	    ~(GEM_INTR_TX_INTME | GEM_INTR_TX_EMPTY | GEM_INTR_RX_DONE |
984 	    GEM_INTR_RX_NOBUF | GEM_INTR_RX_TAG_ERR | GEM_INTR_PERR |
985 	    GEM_INTR_BERR
986 #ifdef GEM_DEBUG
987 	    | GEM_INTR_PCS | GEM_INTR_MIF
988 #endif
989 	    ));
990 	GEM_WRITE_4(sc, GEM_MAC_RX_MASK,
991 	    GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT);
992 	GEM_WRITE_4(sc, GEM_MAC_TX_MASK,
993 	    GEM_MAC_TX_XMIT_DONE | GEM_MAC_TX_DEFER_EXP |
994 	    GEM_MAC_TX_PEAK_EXP);
995 #ifdef GEM_DEBUG
996 	GEM_WRITE_4(sc, GEM_MAC_CONTROL_MASK,
997 	    ~(GEM_MAC_PAUSED | GEM_MAC_PAUSE | GEM_MAC_RESUME));
998 #else
999 	GEM_WRITE_4(sc, GEM_MAC_CONTROL_MASK,
1000 	    GEM_MAC_PAUSED | GEM_MAC_PAUSE | GEM_MAC_RESUME);
1001 #endif
1002 
1003 	/* step 9.  ETX Configuration: use mostly default values. */
1004 
1005 	/* Enable DMA. */
1006 	v = gem_ringsize(GEM_NTXDESC);
1007 	/* Set TX FIFO threshold and enable DMA. */
1008 	v |= (0x4ff << 10) & GEM_TX_CONFIG_TXFIFO_TH;
1009 	GEM_WRITE_4(sc, GEM_TX_CONFIG, v | GEM_TX_CONFIG_TXDMA_EN);
1010 
1011 	/* step 10.  ERX Configuration */
1012 
1013 	/* Encode Receive Descriptor ring size. */
1014 	v = gem_ringsize(GEM_NRXDESC /* XXX */);
1015 	/* RX TCP/UDP checksum offset */
1016 	v |= ((ETHER_HDR_LEN + sizeof(struct ip)) <<
1017 	    GEM_RX_CONFIG_CXM_START_SHFT);
1018 	/* Set RX FIFO threshold, set first byte offset and enable DMA. */
1019 	GEM_WRITE_4(sc, GEM_RX_CONFIG,
1020 	    v | (GEM_THRSH_1024 << GEM_RX_CONFIG_FIFO_THRS_SHIFT) |
1021 	    (ETHER_ALIGN << GEM_RX_CONFIG_FBOFF_SHFT) |
1022 	    GEM_RX_CONFIG_RXDMA_EN);
1023 
1024 	GEM_WRITE_4(sc, GEM_RX_BLANKING,
1025 	    ((6 * (sc->sc_flags & GEM_PCI66) != 0 ? 2 : 1) <<
1026 	    GEM_RX_BLANKING_TIME_SHIFT) | 6);
1027 
1028 	/*
1029 	 * The following value is for an OFF Threshold of about 3/4 full
1030 	 * and an ON Threshold of 1/4 full.
1031 	 */
1032 	GEM_WRITE_4(sc, GEM_RX_PAUSE_THRESH,
1033 	    (3 * sc->sc_rxfifosize / 256) |
1034 	    ((sc->sc_rxfifosize / 256) << 12));
1035 
1036 	/* step 11.  Configure Media. */
1037 
1038 	/* step 12.  RX_MAC Configuration Register */
1039 	v = GEM_READ_4(sc, GEM_MAC_RX_CONFIG);
1040 	v &= ~GEM_MAC_RX_ENABLE;
1041 	v |= GEM_MAC_RX_STRIP_CRC;
1042 	sc->sc_mac_rxcfg = v;
1043 	/*
1044 	 * Clear the RX filter and reprogram it.  This will also set the
1045 	 * current RX MAC configuration and enable it.
1046 	 */
1047 	gem_setladrf(sc);
1048 
1049 	/* step 13.  TX_MAC Configuration Register */
1050 	v = GEM_READ_4(sc, GEM_MAC_TX_CONFIG);
1051 	v |= GEM_MAC_TX_ENABLE;
1052 	(void)gem_disable_tx(sc);
1053 	GEM_WRITE_4(sc, GEM_MAC_TX_CONFIG, v);
1054 
1055 	/* step 14.  Issue Transmit Pending command. */
1056 
1057 	/* step 15.  Give the receiver a swift kick. */
1058 	GEM_WRITE_4(sc, GEM_RX_KICK, GEM_NRXDESC - 4);
1059 
1060 	if_setdrvflagbits(ifp, IFF_DRV_RUNNING, 0);
1061 	if_setdrvflagbits(ifp, 0, IFF_DRV_OACTIVE);
1062 
1063 	mii_mediachg(sc->sc_mii);
1064 
1065 	/* Start the one second timer. */
1066 	sc->sc_wdog_timer = 0;
1067 	callout_reset(&sc->sc_tick_ch, hz, gem_tick, sc);
1068 }
1069 
1070 static int
1071 gem_load_txmbuf(struct gem_softc *sc, struct mbuf **m_head)
1072 {
1073 	bus_dma_segment_t txsegs[GEM_NTXSEGS];
1074 	struct gem_txsoft *txs;
1075 	struct ip *ip;
1076 	struct mbuf *m;
1077 	uint64_t cflags, flags;
1078 	int error, nexttx, nsegs, offset, seg;
1079 
1080 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1081 
1082 	/* Get a work queue entry. */
1083 	if ((txs = STAILQ_FIRST(&sc->sc_txfreeq)) == NULL) {
1084 		/* Ran out of descriptors. */
1085 		return (ENOBUFS);
1086 	}
1087 
1088 	cflags = 0;
1089 	if (((*m_head)->m_pkthdr.csum_flags & sc->sc_csum_features) != 0) {
1090 		if (M_WRITABLE(*m_head) == 0) {
1091 			m = m_dup(*m_head, M_NOWAIT);
1092 			m_freem(*m_head);
1093 			*m_head = m;
1094 			if (m == NULL)
1095 				return (ENOBUFS);
1096 		}
1097 		offset = sizeof(struct ether_header);
1098 		m = m_pullup(*m_head, offset + sizeof(struct ip));
1099 		if (m == NULL) {
1100 			*m_head = NULL;
1101 			return (ENOBUFS);
1102 		}
1103 		ip = (struct ip *)(mtod(m, caddr_t) + offset);
1104 		offset += (ip->ip_hl << 2);
1105 		cflags = offset << GEM_TD_CXSUM_STARTSHFT |
1106 		    ((offset + m->m_pkthdr.csum_data) <<
1107 		    GEM_TD_CXSUM_STUFFSHFT) | GEM_TD_CXSUM_ENABLE;
1108 		*m_head = m;
1109 	}
1110 
1111 	error = bus_dmamap_load_mbuf_sg(sc->sc_tdmatag, txs->txs_dmamap,
1112 	    *m_head, txsegs, &nsegs, BUS_DMA_NOWAIT);
1113 	if (error == EFBIG) {
1114 		m = m_collapse(*m_head, M_NOWAIT, GEM_NTXSEGS);
1115 		if (m == NULL) {
1116 			m_freem(*m_head);
1117 			*m_head = NULL;
1118 			return (ENOBUFS);
1119 		}
1120 		*m_head = m;
1121 		error = bus_dmamap_load_mbuf_sg(sc->sc_tdmatag,
1122 		    txs->txs_dmamap, *m_head, txsegs, &nsegs,
1123 		    BUS_DMA_NOWAIT);
1124 		if (error != 0) {
1125 			m_freem(*m_head);
1126 			*m_head = NULL;
1127 			return (error);
1128 		}
1129 	} else if (error != 0)
1130 		return (error);
1131 	/* If nsegs is wrong then the stack is corrupt. */
1132 	KASSERT(nsegs <= GEM_NTXSEGS,
1133 	    ("%s: too many DMA segments (%d)", __func__, nsegs));
1134 	if (nsegs == 0) {
1135 		m_freem(*m_head);
1136 		*m_head = NULL;
1137 		return (EIO);
1138 	}
1139 
1140 	/*
1141 	 * Ensure we have enough descriptors free to describe
1142 	 * the packet.  Note, we always reserve one descriptor
1143 	 * at the end of the ring as a termination point, in
1144 	 * order to prevent wrap-around.
1145 	 */
1146 	if (nsegs > sc->sc_txfree - 1) {
1147 		txs->txs_ndescs = 0;
1148 		bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
1149 		return (ENOBUFS);
1150 	}
1151 
1152 	txs->txs_ndescs = nsegs;
1153 	txs->txs_firstdesc = sc->sc_txnext;
1154 	nexttx = txs->txs_firstdesc;
1155 	for (seg = 0; seg < nsegs; seg++, nexttx = GEM_NEXTTX(nexttx)) {
1156 #ifdef GEM_DEBUG
1157 		CTR6(KTR_GEM,
1158 		    "%s: mapping seg %d (txd %d), len %lx, addr %#lx (%#lx)",
1159 		    __func__, seg, nexttx, txsegs[seg].ds_len,
1160 		    txsegs[seg].ds_addr, htole64(txsegs[seg].ds_addr));
1161 #endif
1162 		sc->sc_txdescs[nexttx].gd_addr = htole64(txsegs[seg].ds_addr);
1163 		KASSERT(txsegs[seg].ds_len < GEM_TD_BUFSIZE,
1164 		    ("%s: segment size too large!", __func__));
1165 		flags = txsegs[seg].ds_len & GEM_TD_BUFSIZE;
1166 		sc->sc_txdescs[nexttx].gd_flags = htole64(flags | cflags);
1167 		txs->txs_lastdesc = nexttx;
1168 	}
1169 
1170 	/* Set EOP on the last descriptor. */
1171 #ifdef GEM_DEBUG
1172 	CTR3(KTR_GEM, "%s: end of packet at segment %d, TX %d",
1173 	    __func__, seg, nexttx);
1174 #endif
1175 	sc->sc_txdescs[txs->txs_lastdesc].gd_flags |=
1176 	    htole64(GEM_TD_END_OF_PACKET);
1177 
1178 	/* Lastly set SOP on the first descriptor. */
1179 #ifdef GEM_DEBUG
1180 	CTR3(KTR_GEM, "%s: start of packet at segment %d, TX %d",
1181 	    __func__, seg, nexttx);
1182 #endif
1183 	if (++sc->sc_txwin > GEM_NTXSEGS * 2 / 3) {
1184 		sc->sc_txwin = 0;
1185 		sc->sc_txdescs[txs->txs_firstdesc].gd_flags |=
1186 		    htole64(GEM_TD_INTERRUPT_ME | GEM_TD_START_OF_PACKET);
1187 	} else
1188 		sc->sc_txdescs[txs->txs_firstdesc].gd_flags |=
1189 		    htole64(GEM_TD_START_OF_PACKET);
1190 
1191 	/* Sync the DMA map. */
1192 	bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
1193 	    BUS_DMASYNC_PREWRITE);
1194 
1195 #ifdef GEM_DEBUG
1196 	CTR4(KTR_GEM, "%s: setting firstdesc=%d, lastdesc=%d, ndescs=%d",
1197 	    __func__, txs->txs_firstdesc, txs->txs_lastdesc,
1198 	    txs->txs_ndescs);
1199 #endif
1200 	STAILQ_REMOVE_HEAD(&sc->sc_txfreeq, txs_q);
1201 	STAILQ_INSERT_TAIL(&sc->sc_txdirtyq, txs, txs_q);
1202 	txs->txs_mbuf = *m_head;
1203 
1204 	sc->sc_txnext = GEM_NEXTTX(txs->txs_lastdesc);
1205 	sc->sc_txfree -= txs->txs_ndescs;
1206 
1207 	return (0);
1208 }
1209 
1210 static void
1211 gem_init_regs(struct gem_softc *sc)
1212 {
1213 	const u_char *laddr = if_getlladdr(sc->sc_ifp);
1214 
1215 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1216 
1217 	/* These registers are not cleared on reset. */
1218 	if ((sc->sc_flags & GEM_INITED) == 0) {
1219 		/* magic values */
1220 		GEM_WRITE_4(sc, GEM_MAC_IPG0, 0);
1221 		GEM_WRITE_4(sc, GEM_MAC_IPG1, 8);
1222 		GEM_WRITE_4(sc, GEM_MAC_IPG2, 4);
1223 
1224 		/* min frame length */
1225 		GEM_WRITE_4(sc, GEM_MAC_MAC_MIN_FRAME, ETHER_MIN_LEN);
1226 		/* max frame length and max burst size */
1227 		GEM_WRITE_4(sc, GEM_MAC_MAC_MAX_FRAME,
1228 		    (ETHER_MAX_LEN + ETHER_VLAN_ENCAP_LEN) | (0x2000 << 16));
1229 
1230 		/* more magic values */
1231 		GEM_WRITE_4(sc, GEM_MAC_PREAMBLE_LEN, 0x7);
1232 		GEM_WRITE_4(sc, GEM_MAC_JAM_SIZE, 0x4);
1233 		GEM_WRITE_4(sc, GEM_MAC_ATTEMPT_LIMIT, 0x10);
1234 		GEM_WRITE_4(sc, GEM_MAC_CONTROL_TYPE, 0x8808);
1235 
1236 		/* random number seed */
1237 		GEM_WRITE_4(sc, GEM_MAC_RANDOM_SEED,
1238 		    ((laddr[5] << 8) | laddr[4]) & 0x3ff);
1239 
1240 		/* secondary MAC address: 0:0:0:0:0:0 */
1241 		GEM_WRITE_4(sc, GEM_MAC_ADDR3, 0);
1242 		GEM_WRITE_4(sc, GEM_MAC_ADDR4, 0);
1243 		GEM_WRITE_4(sc, GEM_MAC_ADDR5, 0);
1244 
1245 		/* MAC control address: 01:80:c2:00:00:01 */
1246 		GEM_WRITE_4(sc, GEM_MAC_ADDR6, 0x0001);
1247 		GEM_WRITE_4(sc, GEM_MAC_ADDR7, 0xc200);
1248 		GEM_WRITE_4(sc, GEM_MAC_ADDR8, 0x0180);
1249 
1250 		/* MAC filter address: 0:0:0:0:0:0 */
1251 		GEM_WRITE_4(sc, GEM_MAC_ADDR_FILTER0, 0);
1252 		GEM_WRITE_4(sc, GEM_MAC_ADDR_FILTER1, 0);
1253 		GEM_WRITE_4(sc, GEM_MAC_ADDR_FILTER2, 0);
1254 		GEM_WRITE_4(sc, GEM_MAC_ADR_FLT_MASK1_2, 0);
1255 		GEM_WRITE_4(sc, GEM_MAC_ADR_FLT_MASK0, 0);
1256 
1257 		sc->sc_flags |= GEM_INITED;
1258 	}
1259 
1260 	/* Counters need to be zeroed. */
1261 	GEM_WRITE_4(sc, GEM_MAC_NORM_COLL_CNT, 0);
1262 	GEM_WRITE_4(sc, GEM_MAC_FIRST_COLL_CNT, 0);
1263 	GEM_WRITE_4(sc, GEM_MAC_EXCESS_COLL_CNT, 0);
1264 	GEM_WRITE_4(sc, GEM_MAC_LATE_COLL_CNT, 0);
1265 	GEM_WRITE_4(sc, GEM_MAC_DEFER_TMR_CNT, 0);
1266 	GEM_WRITE_4(sc, GEM_MAC_PEAK_ATTEMPTS, 0);
1267 	GEM_WRITE_4(sc, GEM_MAC_RX_FRAME_COUNT, 0);
1268 	GEM_WRITE_4(sc, GEM_MAC_RX_LEN_ERR_CNT, 0);
1269 	GEM_WRITE_4(sc, GEM_MAC_RX_ALIGN_ERR, 0);
1270 	GEM_WRITE_4(sc, GEM_MAC_RX_CRC_ERR_CNT, 0);
1271 	GEM_WRITE_4(sc, GEM_MAC_RX_CODE_VIOL, 0);
1272 
1273 	/* Set XOFF PAUSE time. */
1274 	GEM_WRITE_4(sc, GEM_MAC_SEND_PAUSE_CMD, 0x1BF0);
1275 
1276 	/* Set the station address. */
1277 	GEM_WRITE_4(sc, GEM_MAC_ADDR0, (laddr[4] << 8) | laddr[5]);
1278 	GEM_WRITE_4(sc, GEM_MAC_ADDR1, (laddr[2] << 8) | laddr[3]);
1279 	GEM_WRITE_4(sc, GEM_MAC_ADDR2, (laddr[0] << 8) | laddr[1]);
1280 
1281 	/* Enable MII outputs. */
1282 	GEM_WRITE_4(sc, GEM_MAC_XIF_CONFIG, GEM_MAC_XIF_TX_MII_ENA);
1283 }
1284 
1285 static void
1286 gem_start(if_t ifp)
1287 {
1288 	struct gem_softc *sc = if_getsoftc(ifp);
1289 
1290 	GEM_LOCK(sc);
1291 	gem_start_locked(ifp);
1292 	GEM_UNLOCK(sc);
1293 }
1294 
1295 static inline void
1296 gem_txkick(struct gem_softc *sc)
1297 {
1298 
1299 	/*
1300 	 * Update the TX kick register.  This register has to point to the
1301 	 * descriptor after the last valid one and for optimum performance
1302 	 * should be incremented in multiples of 4 (the DMA engine fetches/
1303 	 * updates descriptors in batches of 4).
1304 	 */
1305 #ifdef GEM_DEBUG
1306 	CTR3(KTR_GEM, "%s: %s: kicking TX %d",
1307 	    device_get_name(sc->sc_dev), __func__, sc->sc_txnext);
1308 #endif
1309 	GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
1310 	GEM_WRITE_4(sc, GEM_TX_KICK, sc->sc_txnext);
1311 }
1312 
1313 static void
1314 gem_start_locked(if_t ifp)
1315 {
1316 	struct gem_softc *sc = if_getsoftc(ifp);
1317 	struct mbuf *m;
1318 	int kicked, ntx;
1319 
1320 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1321 
1322 	if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
1323 	    IFF_DRV_RUNNING || (sc->sc_flags & GEM_LINK) == 0)
1324 		return;
1325 
1326 #ifdef GEM_DEBUG
1327 	CTR4(KTR_GEM, "%s: %s: txfree %d, txnext %d",
1328 	    device_get_name(sc->sc_dev), __func__, sc->sc_txfree,
1329 	    sc->sc_txnext);
1330 #endif
1331 	ntx = 0;
1332 	kicked = 0;
1333 	for (; !if_sendq_empty(ifp) && sc->sc_txfree > 1;) {
1334 		m = if_dequeue(ifp);
1335 		if (m == NULL)
1336 			break;
1337 		if (gem_load_txmbuf(sc, &m) != 0) {
1338 			if (m == NULL)
1339 				break;
1340 			if_setdrvflagbits(ifp, IFF_DRV_OACTIVE, 0);
1341 			if_sendq_prepend(ifp, m);
1342 			break;
1343 		}
1344 		if ((sc->sc_txnext % 4) == 0) {
1345 			gem_txkick(sc);
1346 			kicked = 1;
1347 		} else
1348 			kicked = 0;
1349 		ntx++;
1350 		BPF_MTAP(ifp, m);
1351 	}
1352 
1353 	if (ntx > 0) {
1354 		if (kicked == 0)
1355 			gem_txkick(sc);
1356 #ifdef GEM_DEBUG
1357 		CTR2(KTR_GEM, "%s: packets enqueued, OWN on %d",
1358 		    device_get_name(sc->sc_dev), sc->sc_txnext);
1359 #endif
1360 
1361 		/* Set a watchdog timer in case the chip flakes out. */
1362 		sc->sc_wdog_timer = 5;
1363 #ifdef GEM_DEBUG
1364 		CTR3(KTR_GEM, "%s: %s: watchdog %d",
1365 		    device_get_name(sc->sc_dev), __func__,
1366 		    sc->sc_wdog_timer);
1367 #endif
1368 	}
1369 }
1370 
1371 static void
1372 gem_tint(struct gem_softc *sc)
1373 {
1374 	if_t ifp = sc->sc_ifp;
1375 	struct gem_txsoft *txs;
1376 	int progress;
1377 	uint32_t txlast;
1378 #ifdef GEM_DEBUG
1379 	int i;
1380 
1381 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1382 
1383 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
1384 #endif
1385 
1386 	/*
1387 	 * Go through our TX list and free mbufs for those
1388 	 * frames that have been transmitted.
1389 	 */
1390 	progress = 0;
1391 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD);
1392 	while ((txs = STAILQ_FIRST(&sc->sc_txdirtyq)) != NULL) {
1393 #ifdef GEM_DEBUG
1394 		if ((if_getflags(ifp) & IFF_DEBUG) != 0) {
1395 			printf("    txsoft %p transmit chain:\n", txs);
1396 			for (i = txs->txs_firstdesc;; i = GEM_NEXTTX(i)) {
1397 				printf("descriptor %d: ", i);
1398 				printf("gd_flags: 0x%016llx\t",
1399 				    (long long)le64toh(
1400 				    sc->sc_txdescs[i].gd_flags));
1401 				printf("gd_addr: 0x%016llx\n",
1402 				    (long long)le64toh(
1403 				    sc->sc_txdescs[i].gd_addr));
1404 				if (i == txs->txs_lastdesc)
1405 					break;
1406 			}
1407 		}
1408 #endif
1409 
1410 		/*
1411 		 * In theory, we could harvest some descriptors before
1412 		 * the ring is empty, but that's a bit complicated.
1413 		 *
1414 		 * GEM_TX_COMPLETION points to the last descriptor
1415 		 * processed + 1.
1416 		 */
1417 		txlast = GEM_READ_4(sc, GEM_TX_COMPLETION);
1418 #ifdef GEM_DEBUG
1419 		CTR4(KTR_GEM, "%s: txs->txs_firstdesc = %d, "
1420 		    "txs->txs_lastdesc = %d, txlast = %d",
1421 		    __func__, txs->txs_firstdesc, txs->txs_lastdesc, txlast);
1422 #endif
1423 		if (txs->txs_firstdesc <= txs->txs_lastdesc) {
1424 			if ((txlast >= txs->txs_firstdesc) &&
1425 			    (txlast <= txs->txs_lastdesc))
1426 				break;
1427 		} else {
1428 			/* Ick -- this command wraps. */
1429 			if ((txlast >= txs->txs_firstdesc) ||
1430 			    (txlast <= txs->txs_lastdesc))
1431 				break;
1432 		}
1433 
1434 #ifdef GEM_DEBUG
1435 		CTR1(KTR_GEM, "%s: releasing a descriptor", __func__);
1436 #endif
1437 		STAILQ_REMOVE_HEAD(&sc->sc_txdirtyq, txs_q);
1438 
1439 		sc->sc_txfree += txs->txs_ndescs;
1440 
1441 		bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
1442 		    BUS_DMASYNC_POSTWRITE);
1443 		bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
1444 		if (txs->txs_mbuf != NULL) {
1445 			m_freem(txs->txs_mbuf);
1446 			txs->txs_mbuf = NULL;
1447 		}
1448 
1449 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
1450 
1451 		if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
1452 		progress = 1;
1453 	}
1454 
1455 #ifdef GEM_DEBUG
1456 	CTR4(KTR_GEM, "%s: GEM_TX_STATE_MACHINE %x GEM_TX_DATA_PTR %llx "
1457 	    "GEM_TX_COMPLETION %x",
1458 	    __func__, GEM_READ_4(sc, GEM_TX_STATE_MACHINE),
1459 	    ((long long)GEM_READ_4(sc, GEM_TX_DATA_PTR_HI) << 32) |
1460 	    GEM_READ_4(sc, GEM_TX_DATA_PTR_LO),
1461 	    GEM_READ_4(sc, GEM_TX_COMPLETION));
1462 #endif
1463 
1464 	if (progress) {
1465 		if (sc->sc_txfree == GEM_NTXDESC - 1)
1466 			sc->sc_txwin = 0;
1467 
1468 		/*
1469 		 * We freed some descriptors, so reset IFF_DRV_OACTIVE
1470 		 * and restart.
1471 		 */
1472 		if_setdrvflagbits(ifp, 0, IFF_DRV_OACTIVE);
1473 		if (STAILQ_EMPTY(&sc->sc_txdirtyq))
1474 		    sc->sc_wdog_timer = 0;
1475 		gem_start_locked(ifp);
1476 	}
1477 
1478 #ifdef GEM_DEBUG
1479 	CTR3(KTR_GEM, "%s: %s: watchdog %d",
1480 	    device_get_name(sc->sc_dev), __func__, sc->sc_wdog_timer);
1481 #endif
1482 }
1483 
1484 #ifdef GEM_RINT_TIMEOUT
1485 static void
1486 gem_rint_timeout(void *arg)
1487 {
1488 	struct gem_softc *sc = arg;
1489 
1490 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1491 
1492 	gem_rint(sc);
1493 }
1494 #endif
1495 
1496 static void
1497 gem_rint(struct gem_softc *sc)
1498 {
1499 	if_t ifp = sc->sc_ifp;
1500 	struct mbuf *m;
1501 	uint64_t rxstat;
1502 	uint32_t rxcomp;
1503 
1504 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1505 
1506 #ifdef GEM_RINT_TIMEOUT
1507 	callout_stop(&sc->sc_rx_ch);
1508 #endif
1509 #ifdef GEM_DEBUG
1510 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
1511 #endif
1512 
1513 	/*
1514 	 * Read the completion register once.  This limits
1515 	 * how long the following loop can execute.
1516 	 */
1517 	rxcomp = GEM_READ_4(sc, GEM_RX_COMPLETION);
1518 #ifdef GEM_DEBUG
1519 	CTR3(KTR_GEM, "%s: sc->sc_rxptr %d, complete %d",
1520 	    __func__, sc->sc_rxptr, rxcomp);
1521 #endif
1522 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
1523 	for (; sc->sc_rxptr != rxcomp;) {
1524 		m = sc->sc_rxsoft[sc->sc_rxptr].rxs_mbuf;
1525 		rxstat = le64toh(sc->sc_rxdescs[sc->sc_rxptr].gd_flags);
1526 
1527 		if (rxstat & GEM_RD_OWN) {
1528 #ifdef GEM_RINT_TIMEOUT
1529 			/*
1530 			 * The descriptor is still marked as owned, although
1531 			 * it is supposed to have completed.  This has been
1532 			 * observed on some machines.  Just exiting here
1533 			 * might leave the packet sitting around until another
1534 			 * one arrives to trigger a new interrupt, which is
1535 			 * generally undesirable, so set up a timeout.
1536 			 */
1537 			callout_reset(&sc->sc_rx_ch, GEM_RXOWN_TICKS,
1538 			    gem_rint_timeout, sc);
1539 #endif
1540 			m = NULL;
1541 			goto kickit;
1542 		}
1543 
1544 		if (rxstat & GEM_RD_BAD_CRC) {
1545 			if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
1546 			device_printf(sc->sc_dev, "receive error: CRC error\n");
1547 			GEM_INIT_RXDESC(sc, sc->sc_rxptr);
1548 			m = NULL;
1549 			goto kickit;
1550 		}
1551 
1552 #ifdef GEM_DEBUG
1553 		if ((if_getflags(ifp) & IFF_DEBUG) != 0) {
1554 			printf("    rxsoft %p descriptor %d: ",
1555 			    &sc->sc_rxsoft[sc->sc_rxptr], sc->sc_rxptr);
1556 			printf("gd_flags: 0x%016llx\t",
1557 			    (long long)le64toh(
1558 			    sc->sc_rxdescs[sc->sc_rxptr].gd_flags));
1559 			printf("gd_addr: 0x%016llx\n",
1560 			    (long long)le64toh(
1561 			    sc->sc_rxdescs[sc->sc_rxptr].gd_addr));
1562 		}
1563 #endif
1564 
1565 		/*
1566 		 * Allocate a new mbuf cluster.  If that fails, we are
1567 		 * out of memory, and must drop the packet and recycle
1568 		 * the buffer that's already attached to this descriptor.
1569 		 */
1570 		if (gem_add_rxbuf(sc, sc->sc_rxptr) != 0) {
1571 			if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1572 			GEM_INIT_RXDESC(sc, sc->sc_rxptr);
1573 			m = NULL;
1574 		}
1575 
1576  kickit:
1577 		/*
1578 		 * Update the RX kick register.  This register has to point
1579 		 * to the descriptor after the last valid one (before the
1580 		 * current batch) and for optimum performance should be
1581 		 * incremented in multiples of 4 (the DMA engine fetches/
1582 		 * updates descriptors in batches of 4).
1583 		 */
1584 		sc->sc_rxptr = GEM_NEXTRX(sc->sc_rxptr);
1585 		if ((sc->sc_rxptr % 4) == 0) {
1586 			GEM_CDSYNC(sc,
1587 			    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
1588 			GEM_WRITE_4(sc, GEM_RX_KICK,
1589 			    (sc->sc_rxptr + GEM_NRXDESC - 4) &
1590 			    GEM_NRXDESC_MASK);
1591 		}
1592 
1593 		if (m == NULL) {
1594 			if (rxstat & GEM_RD_OWN)
1595 				break;
1596 			continue;
1597 		}
1598 
1599 		if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1600 		m->m_data += ETHER_ALIGN; /* first byte offset */
1601 		m->m_pkthdr.rcvif = ifp;
1602 		m->m_pkthdr.len = m->m_len = GEM_RD_BUFLEN(rxstat);
1603 
1604 		if ((if_getcapenable(ifp) & IFCAP_RXCSUM) != 0)
1605 			gem_rxcksum(m, rxstat);
1606 
1607 		/* Pass it on. */
1608 		GEM_UNLOCK(sc);
1609 		if_input(ifp, m);
1610 		GEM_LOCK(sc);
1611 	}
1612 
1613 #ifdef GEM_DEBUG
1614 	CTR3(KTR_GEM, "%s: done sc->sc_rxptr %d, complete %d", __func__,
1615 	    sc->sc_rxptr, GEM_READ_4(sc, GEM_RX_COMPLETION));
1616 #endif
1617 }
1618 
1619 static int
1620 gem_add_rxbuf(struct gem_softc *sc, int idx)
1621 {
1622 	struct gem_rxsoft *rxs = &sc->sc_rxsoft[idx];
1623 	struct mbuf *m;
1624 	bus_dma_segment_t segs[1];
1625 	int error, nsegs;
1626 
1627 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1628 
1629 	m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
1630 	if (m == NULL)
1631 		return (ENOBUFS);
1632 	m->m_len = m->m_pkthdr.len = m->m_ext.ext_size;
1633 
1634 #ifdef GEM_DEBUG
1635 	/* Bzero the packet to check DMA. */
1636 	memset(m->m_ext.ext_buf, 0, m->m_ext.ext_size);
1637 #endif
1638 
1639 	if (rxs->rxs_mbuf != NULL) {
1640 		bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
1641 		    BUS_DMASYNC_POSTREAD);
1642 		bus_dmamap_unload(sc->sc_rdmatag, rxs->rxs_dmamap);
1643 	}
1644 
1645 	error = bus_dmamap_load_mbuf_sg(sc->sc_rdmatag, rxs->rxs_dmamap,
1646 	    m, segs, &nsegs, BUS_DMA_NOWAIT);
1647 	if (error != 0) {
1648 		device_printf(sc->sc_dev,
1649 		    "cannot load RS DMA map %d, error = %d\n", idx, error);
1650 		m_freem(m);
1651 		return (error);
1652 	}
1653 	/* If nsegs is wrong then the stack is corrupt. */
1654 	KASSERT(nsegs == 1,
1655 	    ("%s: too many DMA segments (%d)", __func__, nsegs));
1656 	rxs->rxs_mbuf = m;
1657 	rxs->rxs_paddr = segs[0].ds_addr;
1658 
1659 	bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
1660 	    BUS_DMASYNC_PREREAD);
1661 
1662 	GEM_INIT_RXDESC(sc, idx);
1663 
1664 	return (0);
1665 }
1666 
1667 static void
1668 gem_eint(struct gem_softc *sc, u_int status)
1669 {
1670 
1671 	if_inc_counter(sc->sc_ifp, IFCOUNTER_IERRORS, 1);
1672 	if ((status & GEM_INTR_RX_TAG_ERR) != 0) {
1673 		gem_reset_rxdma(sc);
1674 		return;
1675 	}
1676 
1677 	device_printf(sc->sc_dev, "%s: status 0x%x", __func__, status);
1678 	if ((status & GEM_INTR_BERR) != 0) {
1679 		printf(", PCI bus error 0x%x",
1680 		    GEM_READ_4(sc, GEM_PCI_ERROR_STATUS));
1681 	}
1682 	printf("\n");
1683 }
1684 
1685 void
1686 gem_intr(void *v)
1687 {
1688 	struct gem_softc *sc = v;
1689 	uint32_t status, status2;
1690 
1691 	GEM_LOCK(sc);
1692 	status = GEM_READ_4(sc, GEM_STATUS);
1693 
1694 #ifdef GEM_DEBUG
1695 	CTR4(KTR_GEM, "%s: %s: cplt %x, status %x",
1696 	    device_get_name(sc->sc_dev), __func__,
1697 	    (status >> GEM_STATUS_TX_COMPLETION_SHFT), (u_int)status);
1698 
1699 	/*
1700 	 * PCS interrupts must be cleared, otherwise no traffic is passed!
1701 	 */
1702 	if ((status & GEM_INTR_PCS) != 0) {
1703 		status2 =
1704 		    GEM_READ_4(sc, GEM_MII_INTERRUP_STATUS) |
1705 		    GEM_READ_4(sc, GEM_MII_INTERRUP_STATUS);
1706 		if ((status2 & GEM_MII_INTERRUP_LINK) != 0)
1707 			device_printf(sc->sc_dev,
1708 			    "%s: PCS link status changed\n", __func__);
1709 	}
1710 	if ((status & GEM_MAC_CONTROL_STATUS) != 0) {
1711 		status2 = GEM_READ_4(sc, GEM_MAC_CONTROL_STATUS);
1712 		if ((status2 & GEM_MAC_PAUSED) != 0)
1713 			device_printf(sc->sc_dev,
1714 			    "%s: PAUSE received (PAUSE time %d slots)\n",
1715 			    __func__, GEM_MAC_PAUSE_TIME(status2));
1716 		if ((status2 & GEM_MAC_PAUSE) != 0)
1717 			device_printf(sc->sc_dev,
1718 			    "%s: transited to PAUSE state\n", __func__);
1719 		if ((status2 & GEM_MAC_RESUME) != 0)
1720 			device_printf(sc->sc_dev,
1721 			    "%s: transited to non-PAUSE state\n", __func__);
1722 	}
1723 	if ((status & GEM_INTR_MIF) != 0)
1724 		device_printf(sc->sc_dev, "%s: MIF interrupt\n", __func__);
1725 #endif
1726 
1727 	if (__predict_false(status &
1728 	    (GEM_INTR_RX_TAG_ERR | GEM_INTR_PERR | GEM_INTR_BERR)) != 0)
1729 		gem_eint(sc, status);
1730 
1731 	if ((status & (GEM_INTR_RX_DONE | GEM_INTR_RX_NOBUF)) != 0)
1732 		gem_rint(sc);
1733 
1734 	if ((status & (GEM_INTR_TX_EMPTY | GEM_INTR_TX_INTME)) != 0)
1735 		gem_tint(sc);
1736 
1737 	if (__predict_false((status & GEM_INTR_TX_MAC) != 0)) {
1738 		status2 = GEM_READ_4(sc, GEM_MAC_TX_STATUS);
1739 		if ((status2 &
1740 		    ~(GEM_MAC_TX_XMIT_DONE | GEM_MAC_TX_DEFER_EXP |
1741 		    GEM_MAC_TX_PEAK_EXP)) != 0)
1742 			device_printf(sc->sc_dev,
1743 			    "MAC TX fault, status %x\n", status2);
1744 		if ((status2 &
1745 		    (GEM_MAC_TX_UNDERRUN | GEM_MAC_TX_PKT_TOO_LONG)) != 0) {
1746 			if_inc_counter(sc->sc_ifp, IFCOUNTER_OERRORS, 1);
1747 			if_setdrvflagbits(sc->sc_ifp, 0, IFF_DRV_RUNNING);
1748 			gem_init_locked(sc);
1749 		}
1750 	}
1751 	if (__predict_false((status & GEM_INTR_RX_MAC) != 0)) {
1752 		status2 = GEM_READ_4(sc, GEM_MAC_RX_STATUS);
1753 		/*
1754 		 * At least with GEM_SUN_GEM revisions GEM_MAC_RX_OVERFLOW
1755 		 * happen often due to a silicon bug so handle them silently.
1756 		 * Moreover, it's likely that the receiver has hung so we
1757 		 * reset it.
1758 		 */
1759 		if ((status2 & GEM_MAC_RX_OVERFLOW) != 0) {
1760 			if_inc_counter(sc->sc_ifp, IFCOUNTER_IERRORS, 1);
1761 			gem_reset_rxdma(sc);
1762 		} else if ((status2 &
1763 		    ~(GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT)) != 0)
1764 			device_printf(sc->sc_dev,
1765 			    "MAC RX fault, status %x\n", status2);
1766 	}
1767 	GEM_UNLOCK(sc);
1768 }
1769 
1770 static int
1771 gem_watchdog(struct gem_softc *sc)
1772 {
1773 	if_t ifp = sc->sc_ifp;
1774 
1775 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1776 
1777 #ifdef GEM_DEBUG
1778 	CTR4(KTR_GEM,
1779 	    "%s: GEM_RX_CONFIG %x GEM_MAC_RX_STATUS %x GEM_MAC_RX_CONFIG %x",
1780 	    __func__, GEM_READ_4(sc, GEM_RX_CONFIG),
1781 	    GEM_READ_4(sc, GEM_MAC_RX_STATUS),
1782 	    GEM_READ_4(sc, GEM_MAC_RX_CONFIG));
1783 	CTR4(KTR_GEM,
1784 	    "%s: GEM_TX_CONFIG %x GEM_MAC_TX_STATUS %x GEM_MAC_TX_CONFIG %x",
1785 	    __func__, GEM_READ_4(sc, GEM_TX_CONFIG),
1786 	    GEM_READ_4(sc, GEM_MAC_TX_STATUS),
1787 	    GEM_READ_4(sc, GEM_MAC_TX_CONFIG));
1788 #endif
1789 
1790 	if (sc->sc_wdog_timer == 0 || --sc->sc_wdog_timer != 0)
1791 		return (0);
1792 
1793 	if ((sc->sc_flags & GEM_LINK) != 0)
1794 		device_printf(sc->sc_dev, "device timeout\n");
1795 	else if (bootverbose)
1796 		device_printf(sc->sc_dev, "device timeout (no link)\n");
1797 	if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1798 
1799 	/* Try to get more packets going. */
1800 	if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
1801 	gem_init_locked(sc);
1802 	gem_start_locked(ifp);
1803 	return (EJUSTRETURN);
1804 }
1805 
1806 static void
1807 gem_mifinit(struct gem_softc *sc)
1808 {
1809 
1810 	/* Configure the MIF in frame mode. */
1811 	GEM_WRITE_4(sc, GEM_MIF_CONFIG,
1812 	    GEM_READ_4(sc, GEM_MIF_CONFIG) & ~GEM_MIF_CONFIG_BB_ENA);
1813 	GEM_BARRIER(sc, GEM_MIF_CONFIG, 4,
1814 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1815 }
1816 
1817 /*
1818  * MII interface
1819  *
1820  * The MII interface supports at least three different operating modes:
1821  *
1822  * Bitbang mode is implemented using data, clock and output enable registers.
1823  *
1824  * Frame mode is implemented by loading a complete frame into the frame
1825  * register and polling the valid bit for completion.
1826  *
1827  * Polling mode uses the frame register but completion is indicated by
1828  * an interrupt.
1829  *
1830  */
1831 int
1832 gem_mii_readreg(device_t dev, int phy, int reg)
1833 {
1834 	struct gem_softc *sc;
1835 	int n;
1836 	uint32_t v;
1837 
1838 #ifdef GEM_DEBUG_PHY
1839 	printf("%s: phy %d reg %d\n", __func__, phy, reg);
1840 #endif
1841 
1842 	sc = device_get_softc(dev);
1843 	if ((sc->sc_flags & GEM_SERDES) != 0) {
1844 		switch (reg) {
1845 		case MII_BMCR:
1846 			reg = GEM_MII_CONTROL;
1847 			break;
1848 		case MII_BMSR:
1849 			reg = GEM_MII_STATUS;
1850 			break;
1851 		case MII_PHYIDR1:
1852 		case MII_PHYIDR2:
1853 			return (0);
1854 		case MII_ANAR:
1855 			reg = GEM_MII_ANAR;
1856 			break;
1857 		case MII_ANLPAR:
1858 			reg = GEM_MII_ANLPAR;
1859 			break;
1860 		case MII_EXTSR:
1861 			return (EXTSR_1000XFDX | EXTSR_1000XHDX);
1862 		default:
1863 			device_printf(sc->sc_dev,
1864 			    "%s: unhandled register %d\n", __func__, reg);
1865 			return (0);
1866 		}
1867 		return (GEM_READ_4(sc, reg));
1868 	}
1869 
1870 	/* Construct the frame command. */
1871 	v = GEM_MIF_FRAME_READ |
1872 	    (phy << GEM_MIF_PHY_SHIFT) |
1873 	    (reg << GEM_MIF_REG_SHIFT);
1874 
1875 	GEM_WRITE_4(sc, GEM_MIF_FRAME, v);
1876 	GEM_BARRIER(sc, GEM_MIF_FRAME, 4,
1877 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1878 	for (n = 0; n < 100; n++) {
1879 		DELAY(1);
1880 		v = GEM_READ_4(sc, GEM_MIF_FRAME);
1881 		if (v & GEM_MIF_FRAME_TA0)
1882 			return (v & GEM_MIF_FRAME_DATA);
1883 	}
1884 
1885 	device_printf(sc->sc_dev, "%s: timed out\n", __func__);
1886 	return (0);
1887 }
1888 
1889 int
1890 gem_mii_writereg(device_t dev, int phy, int reg, int val)
1891 {
1892 	struct gem_softc *sc;
1893 	int n;
1894 	uint32_t v;
1895 
1896 #ifdef GEM_DEBUG_PHY
1897 	printf("%s: phy %d reg %d val %x\n", phy, reg, val, __func__);
1898 #endif
1899 
1900 	sc = device_get_softc(dev);
1901 	if ((sc->sc_flags & GEM_SERDES) != 0) {
1902 		switch (reg) {
1903 		case MII_BMSR:
1904 			reg = GEM_MII_STATUS;
1905 			break;
1906 		case MII_BMCR:
1907 			reg = GEM_MII_CONTROL;
1908 			if ((val & GEM_MII_CONTROL_RESET) == 0)
1909 				break;
1910 			GEM_WRITE_4(sc, GEM_MII_CONTROL, val);
1911 			GEM_BARRIER(sc, GEM_MII_CONTROL, 4,
1912 			    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1913 			if (!gem_bitwait(sc, GEM_MII_CONTROL,
1914 			    GEM_MII_CONTROL_RESET, 0))
1915 				device_printf(sc->sc_dev,
1916 				    "cannot reset PCS\n");
1917 			/* FALLTHROUGH */
1918 		case MII_ANAR:
1919 			GEM_WRITE_4(sc, GEM_MII_CONFIG, 0);
1920 			GEM_BARRIER(sc, GEM_MII_CONFIG, 4,
1921 			    BUS_SPACE_BARRIER_WRITE);
1922 			GEM_WRITE_4(sc, GEM_MII_ANAR, val);
1923 			GEM_BARRIER(sc, GEM_MII_ANAR, 4,
1924 			    BUS_SPACE_BARRIER_WRITE);
1925 			GEM_WRITE_4(sc, GEM_MII_SLINK_CONTROL,
1926 			    GEM_MII_SLINK_LOOPBACK | GEM_MII_SLINK_EN_SYNC_D);
1927 			GEM_BARRIER(sc, GEM_MII_SLINK_CONTROL, 4,
1928 			    BUS_SPACE_BARRIER_WRITE);
1929 			GEM_WRITE_4(sc, GEM_MII_CONFIG,
1930 			    GEM_MII_CONFIG_ENABLE);
1931 			GEM_BARRIER(sc, GEM_MII_CONFIG, 4,
1932 			    BUS_SPACE_BARRIER_WRITE);
1933 			return (0);
1934 		case MII_ANLPAR:
1935 			reg = GEM_MII_ANLPAR;
1936 			break;
1937 		default:
1938 			device_printf(sc->sc_dev,
1939 			    "%s: unhandled register %d\n", __func__, reg);
1940 			return (0);
1941 		}
1942 		GEM_WRITE_4(sc, reg, val);
1943 		GEM_BARRIER(sc, reg, 4,
1944 		    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1945 		return (0);
1946 	}
1947 
1948 	/* Construct the frame command. */
1949 	v = GEM_MIF_FRAME_WRITE |
1950 	    (phy << GEM_MIF_PHY_SHIFT) |
1951 	    (reg << GEM_MIF_REG_SHIFT) |
1952 	    (val & GEM_MIF_FRAME_DATA);
1953 
1954 	GEM_WRITE_4(sc, GEM_MIF_FRAME, v);
1955 	GEM_BARRIER(sc, GEM_MIF_FRAME, 4,
1956 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
1957 	for (n = 0; n < 100; n++) {
1958 		DELAY(1);
1959 		v = GEM_READ_4(sc, GEM_MIF_FRAME);
1960 		if (v & GEM_MIF_FRAME_TA0)
1961 			return (1);
1962 	}
1963 
1964 	device_printf(sc->sc_dev, "%s: timed out\n", __func__);
1965 	return (0);
1966 }
1967 
1968 void
1969 gem_mii_statchg(device_t dev)
1970 {
1971 	struct gem_softc *sc;
1972 	int gigabit;
1973 	uint32_t rxcfg, txcfg, v;
1974 
1975 	sc = device_get_softc(dev);
1976 
1977 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1978 
1979 #ifdef GEM_DEBUG
1980 	if ((sc->sc_if_getflags(ifp) & IFF_DEBUG) != 0)
1981 		device_printf(sc->sc_dev, "%s: status change\n", __func__);
1982 #endif
1983 
1984 	if ((sc->sc_mii->mii_media_status & IFM_ACTIVE) != 0 &&
1985 	    IFM_SUBTYPE(sc->sc_mii->mii_media_active) != IFM_NONE)
1986 		sc->sc_flags |= GEM_LINK;
1987 	else
1988 		sc->sc_flags &= ~GEM_LINK;
1989 
1990 	switch (IFM_SUBTYPE(sc->sc_mii->mii_media_active)) {
1991 	case IFM_1000_SX:
1992 	case IFM_1000_LX:
1993 	case IFM_1000_CX:
1994 	case IFM_1000_T:
1995 		gigabit = 1;
1996 		break;
1997 	default:
1998 		gigabit = 0;
1999 	}
2000 
2001 	/*
2002 	 * The configuration done here corresponds to the steps F) and
2003 	 * G) and as far as enabling of RX and TX MAC goes also step H)
2004 	 * of the initialization sequence outlined in section 3.2.1 of
2005 	 * the GEM Gigabit Ethernet ASIC Specification.
2006 	 */
2007 
2008 	rxcfg = sc->sc_mac_rxcfg;
2009 	rxcfg &= ~GEM_MAC_RX_CARR_EXTEND;
2010 	txcfg = GEM_MAC_TX_ENA_IPG0 | GEM_MAC_TX_NGU | GEM_MAC_TX_NGU_LIMIT;
2011 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) != 0)
2012 		txcfg |= GEM_MAC_TX_IGN_CARRIER | GEM_MAC_TX_IGN_COLLIS;
2013 	else if (gigabit != 0) {
2014 		rxcfg |= GEM_MAC_RX_CARR_EXTEND;
2015 		txcfg |= GEM_MAC_TX_CARR_EXTEND;
2016 	}
2017 	(void)gem_disable_tx(sc);
2018 	GEM_WRITE_4(sc, GEM_MAC_TX_CONFIG, txcfg);
2019 	(void)gem_disable_rx(sc);
2020 	GEM_WRITE_4(sc, GEM_MAC_RX_CONFIG, rxcfg);
2021 
2022 	v = GEM_READ_4(sc, GEM_MAC_CONTROL_CONFIG) &
2023 	    ~(GEM_MAC_CC_RX_PAUSE | GEM_MAC_CC_TX_PAUSE);
2024 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
2025 	    IFM_ETH_RXPAUSE) != 0)
2026 		v |= GEM_MAC_CC_RX_PAUSE;
2027 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
2028 	    IFM_ETH_TXPAUSE) != 0)
2029 		v |= GEM_MAC_CC_TX_PAUSE;
2030 	GEM_WRITE_4(sc, GEM_MAC_CONTROL_CONFIG, v);
2031 
2032 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) == 0 &&
2033 	    gigabit != 0)
2034 		GEM_WRITE_4(sc, GEM_MAC_SLOT_TIME,
2035 		    GEM_MAC_SLOT_TIME_CARR_EXTEND);
2036 	else
2037 		GEM_WRITE_4(sc, GEM_MAC_SLOT_TIME,
2038 		    GEM_MAC_SLOT_TIME_NORMAL);
2039 
2040 	/* XIF Configuration */
2041 	v = GEM_MAC_XIF_LINK_LED;
2042 	v |= GEM_MAC_XIF_TX_MII_ENA;
2043 	if ((sc->sc_flags & GEM_SERDES) == 0) {
2044 		if ((GEM_READ_4(sc, GEM_MIF_CONFIG) &
2045 		    GEM_MIF_CONFIG_PHY_SEL) != 0) {
2046 			/* External MII needs echo disable if half duplex. */
2047 			if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) &
2048 			    IFM_FDX) == 0)
2049 				v |= GEM_MAC_XIF_ECHO_DISABL;
2050 		} else
2051 			/*
2052 			 * Internal MII needs buffer enable.
2053 			 * XXX buffer enable makes only sense for an
2054 			 * external PHY.
2055 			 */
2056 			v |= GEM_MAC_XIF_MII_BUF_ENA;
2057 	}
2058 	if (gigabit != 0)
2059 		v |= GEM_MAC_XIF_GMII_MODE;
2060 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) != 0)
2061 		v |= GEM_MAC_XIF_FDPLX_LED;
2062 	GEM_WRITE_4(sc, GEM_MAC_XIF_CONFIG, v);
2063 
2064 	sc->sc_mac_rxcfg = rxcfg;
2065 	if ((if_getdrvflags(sc->sc_ifp) & IFF_DRV_RUNNING) != 0 &&
2066 	    (sc->sc_flags & GEM_LINK) != 0) {
2067 		GEM_WRITE_4(sc, GEM_MAC_TX_CONFIG,
2068 		    txcfg | GEM_MAC_TX_ENABLE);
2069 		GEM_WRITE_4(sc, GEM_MAC_RX_CONFIG,
2070 		    rxcfg | GEM_MAC_RX_ENABLE);
2071 	}
2072 }
2073 
2074 int
2075 gem_mediachange(if_t ifp)
2076 {
2077 	struct gem_softc *sc = if_getsoftc(ifp);
2078 	int error;
2079 
2080 	/* XXX add support for serial media. */
2081 
2082 	GEM_LOCK(sc);
2083 	error = mii_mediachg(sc->sc_mii);
2084 	GEM_UNLOCK(sc);
2085 	return (error);
2086 }
2087 
2088 void
2089 gem_mediastatus(if_t ifp, struct ifmediareq *ifmr)
2090 {
2091 	struct gem_softc *sc = if_getsoftc(ifp);
2092 
2093 	GEM_LOCK(sc);
2094 	if ((if_getflags(ifp) & IFF_UP) == 0) {
2095 		GEM_UNLOCK(sc);
2096 		return;
2097 	}
2098 
2099 	mii_pollstat(sc->sc_mii);
2100 	ifmr->ifm_active = sc->sc_mii->mii_media_active;
2101 	ifmr->ifm_status = sc->sc_mii->mii_media_status;
2102 	GEM_UNLOCK(sc);
2103 }
2104 
2105 static int
2106 gem_ioctl(if_t ifp, u_long cmd, caddr_t data)
2107 {
2108 	struct gem_softc *sc = if_getsoftc(ifp);
2109 	struct ifreq *ifr = (struct ifreq *)data;
2110 	int error;
2111 
2112 	error = 0;
2113 	switch (cmd) {
2114 	case SIOCSIFFLAGS:
2115 		GEM_LOCK(sc);
2116 		if ((if_getflags(ifp) & IFF_UP) != 0) {
2117 			if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0 &&
2118 			    ((if_getflags(ifp) ^ sc->sc_ifflags) &
2119 			    (IFF_ALLMULTI | IFF_PROMISC)) != 0)
2120 				gem_setladrf(sc);
2121 			else
2122 				gem_init_locked(sc);
2123 		} else if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0)
2124 			gem_stop(ifp, 0);
2125 		if ((if_getflags(ifp) & IFF_LINK0) != 0)
2126 			sc->sc_csum_features |= CSUM_UDP;
2127 		else
2128 			sc->sc_csum_features &= ~CSUM_UDP;
2129 		if ((if_getcapenable(ifp) & IFCAP_TXCSUM) != 0)
2130 			if_sethwassist(ifp, sc->sc_csum_features);
2131 		sc->sc_ifflags = if_getflags(ifp);
2132 		GEM_UNLOCK(sc);
2133 		break;
2134 	case SIOCADDMULTI:
2135 	case SIOCDELMULTI:
2136 		GEM_LOCK(sc);
2137 		if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0)
2138 			gem_setladrf(sc);
2139 		GEM_UNLOCK(sc);
2140 		break;
2141 	case SIOCGIFMEDIA:
2142 	case SIOCSIFMEDIA:
2143 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_mii->mii_media, cmd);
2144 		break;
2145 	case SIOCSIFCAP:
2146 		GEM_LOCK(sc);
2147 		if_setcapenable(ifp, ifr->ifr_reqcap);
2148 		if ((if_getcapenable(ifp) & IFCAP_TXCSUM) != 0)
2149 			if_sethwassist(ifp, sc->sc_csum_features);
2150 		else
2151 			if_sethwassist(ifp, 0);
2152 		GEM_UNLOCK(sc);
2153 		break;
2154 	default:
2155 		error = ether_ioctl(ifp, cmd, data);
2156 		break;
2157 	}
2158 
2159 	return (error);
2160 }
2161 
2162 static u_int
2163 gem_hash_maddr(void *arg, struct sockaddr_dl *sdl, u_int cnt)
2164 {
2165 	uint32_t crc, *hash = arg;
2166 
2167 	crc = ether_crc32_le(LLADDR(sdl), ETHER_ADDR_LEN);
2168 	/* We just want the 8 most significant bits. */
2169 	crc >>= 24;
2170 	/* Set the corresponding bit in the filter. */
2171 	hash[crc >> 4] |= 1 << (15 - (crc & 15));
2172 
2173 	return (1);
2174 }
2175 
2176 static void
2177 gem_setladrf(struct gem_softc *sc)
2178 {
2179 	if_t ifp = sc->sc_ifp;
2180 	int i;
2181 	uint32_t hash[16];
2182 	uint32_t v;
2183 
2184 	GEM_LOCK_ASSERT(sc, MA_OWNED);
2185 
2186 	/*
2187 	 * Turn off the RX MAC and the hash filter as required by the Sun GEM
2188 	 * programming restrictions.
2189 	 */
2190 	v = sc->sc_mac_rxcfg & ~GEM_MAC_RX_HASH_FILTER;
2191 	GEM_WRITE_4(sc, GEM_MAC_RX_CONFIG, v);
2192 	GEM_BARRIER(sc, GEM_MAC_RX_CONFIG, 4,
2193 	    BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
2194 	if (!gem_bitwait(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_HASH_FILTER |
2195 	    GEM_MAC_RX_ENABLE, 0))
2196 		device_printf(sc->sc_dev,
2197 		    "cannot disable RX MAC or hash filter\n");
2198 
2199 	v &= ~(GEM_MAC_RX_PROMISCUOUS | GEM_MAC_RX_PROMISC_GRP);
2200 	if ((if_getflags(ifp) & IFF_PROMISC) != 0) {
2201 		v |= GEM_MAC_RX_PROMISCUOUS;
2202 		goto chipit;
2203 	}
2204 	if ((if_getflags(ifp) & IFF_ALLMULTI) != 0) {
2205 		v |= GEM_MAC_RX_PROMISC_GRP;
2206 		goto chipit;
2207 	}
2208 
2209 	/*
2210 	 * Set up multicast address filter by passing all multicast
2211 	 * addresses through a crc generator, and then using the high
2212 	 * order 8 bits as an index into the 256 bit logical address
2213 	 * filter.  The high order 4 bits selects the word, while the
2214 	 * other 4 bits select the bit within the word (where bit 0
2215 	 * is the MSB).
2216 	 */
2217 
2218 	memset(hash, 0, sizeof(hash));
2219 	if_foreach_llmaddr(ifp, gem_hash_maddr, hash);
2220 
2221 	v |= GEM_MAC_RX_HASH_FILTER;
2222 
2223 	/* Now load the hash table into the chip (if we are using it). */
2224 	for (i = 0; i < 16; i++)
2225 		GEM_WRITE_4(sc,
2226 		    GEM_MAC_HASH0 + i * (GEM_MAC_HASH1 - GEM_MAC_HASH0),
2227 		    hash[i]);
2228 
2229  chipit:
2230 	sc->sc_mac_rxcfg = v;
2231 	GEM_WRITE_4(sc, GEM_MAC_RX_CONFIG, v | GEM_MAC_RX_ENABLE);
2232 }
2233