xref: /freebsd/sys/dev/gem/if_gem.c (revision b28624fde638caadd4a89f50c9b7e7da0f98c4d2)
1 /*-
2  * Copyright (C) 2001 Eduardo Horvath.
3  * Copyright (c) 2001-2003 Thomas Moestl
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR  ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR  BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  *	from: NetBSD: gem.c,v 1.21 2002/06/01 23:50:58 lukem Exp
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 /*
34  * Driver for Sun GEM ethernet controllers.
35  */
36 
37 #if 0
38 #define	GEM_DEBUG
39 #endif
40 
41 #if 0	/* XXX: In case of emergency, re-enable this. */
42 #define	GEM_RINT_TIMEOUT
43 #endif
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/bus.h>
48 #include <sys/callout.h>
49 #include <sys/endian.h>
50 #include <sys/mbuf.h>
51 #include <sys/malloc.h>
52 #include <sys/kernel.h>
53 #include <sys/lock.h>
54 #include <sys/module.h>
55 #include <sys/mutex.h>
56 #include <sys/socket.h>
57 #include <sys/sockio.h>
58 #include <sys/rman.h>
59 
60 #include <net/bpf.h>
61 #include <net/ethernet.h>
62 #include <net/if.h>
63 #include <net/if_arp.h>
64 #include <net/if_dl.h>
65 #include <net/if_media.h>
66 #include <net/if_types.h>
67 #include <net/if_vlan_var.h>
68 
69 #include <netinet/in.h>
70 #include <netinet/in_systm.h>
71 #include <netinet/ip.h>
72 #include <netinet/tcp.h>
73 #include <netinet/udp.h>
74 
75 #include <machine/bus.h>
76 
77 #include <dev/mii/mii.h>
78 #include <dev/mii/miivar.h>
79 
80 #include <dev/gem/if_gemreg.h>
81 #include <dev/gem/if_gemvar.h>
82 
83 #define TRIES	10000
84 /*
85  * The GEM hardware support basic TCP/UDP checksum offloading. However,
86  * the hardware doesn't compensate the checksum for UDP datagram which
87  * can yield to 0x0. As a safe guard, UDP checksum offload is disabled
88  * by default. It can be reactivated by setting special link option
89  * link0 with ifconfig(8).
90  */
91 #define	GEM_CSUM_FEATURES	(CSUM_TCP)
92 
93 static void	gem_start(struct ifnet *);
94 static void	gem_start_locked(struct ifnet *);
95 static void	gem_stop(struct ifnet *, int);
96 static int	gem_ioctl(struct ifnet *, u_long, caddr_t);
97 static void	gem_cddma_callback(void *, bus_dma_segment_t *, int, int);
98 static __inline void gem_txcksum(struct gem_softc *, struct mbuf *, uint64_t *);
99 static __inline void gem_rxcksum(struct mbuf *, uint64_t);
100 static void	gem_tick(void *);
101 static int	gem_watchdog(struct gem_softc *);
102 static void	gem_init(void *);
103 static void	gem_init_locked(struct gem_softc *);
104 static void	gem_init_regs(struct gem_softc *);
105 static int	gem_ringsize(int sz);
106 static int	gem_meminit(struct gem_softc *);
107 static struct mbuf *gem_defrag(struct mbuf *, int, int);
108 static int	gem_load_txmbuf(struct gem_softc *, struct mbuf **);
109 static void	gem_mifinit(struct gem_softc *);
110 static int	gem_bitwait(struct gem_softc *, bus_addr_t, u_int32_t,
111     u_int32_t);
112 static int	gem_reset_rx(struct gem_softc *);
113 static int	gem_reset_tx(struct gem_softc *);
114 static int	gem_disable_rx(struct gem_softc *);
115 static int	gem_disable_tx(struct gem_softc *);
116 static void	gem_rxdrain(struct gem_softc *);
117 static int	gem_add_rxbuf(struct gem_softc *, int);
118 static void	gem_setladrf(struct gem_softc *);
119 
120 struct mbuf	*gem_get(struct gem_softc *, int, int);
121 static void	gem_eint(struct gem_softc *, u_int);
122 static void	gem_rint(struct gem_softc *);
123 #ifdef GEM_RINT_TIMEOUT
124 static void	gem_rint_timeout(void *);
125 #endif
126 static void	gem_tint(struct gem_softc *);
127 #ifdef notyet
128 static void	gem_power(int, void *);
129 #endif
130 
131 devclass_t gem_devclass;
132 DRIVER_MODULE(miibus, gem, miibus_driver, miibus_devclass, 0, 0);
133 MODULE_DEPEND(gem, miibus, 1, 1, 1);
134 
135 #ifdef GEM_DEBUG
136 #include <sys/ktr.h>
137 #define	KTR_GEM		KTR_CT2
138 #endif
139 
140 #define	GEM_NSEGS GEM_NTXDESC
141 
142 /*
143  * gem_attach:
144  *
145  *	Attach a Gem interface to the system.
146  */
147 int
148 gem_attach(sc)
149 	struct gem_softc *sc;
150 {
151 	struct ifnet *ifp;
152 	struct mii_softc *child;
153 	int i, error;
154 	u_int32_t v;
155 
156 	ifp = sc->sc_ifp = if_alloc(IFT_ETHER);
157 	if (ifp == NULL)
158 		return (ENOSPC);
159 
160 	callout_init_mtx(&sc->sc_tick_ch, &sc->sc_mtx, 0);
161 #ifdef GEM_RINT_TIMEOUT
162 	callout_init_mtx(&sc->sc_rx_ch, &sc->sc_mtx, 0);
163 #endif
164 
165 	/* Make sure the chip is stopped. */
166 	ifp->if_softc = sc;
167 	GEM_LOCK(sc);
168 	gem_stop(ifp, 0);
169 	gem_reset(sc);
170 	GEM_UNLOCK(sc);
171 
172 	error = bus_dma_tag_create(bus_get_dma_tag(sc->sc_dev), 1, 0,
173 	    BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
174 	    BUS_SPACE_MAXSIZE_32BIT, 0, BUS_SPACE_MAXSIZE_32BIT, 0, NULL, NULL,
175 	    &sc->sc_pdmatag);
176 	if (error)
177 		goto fail_ifnet;
178 
179 	error = bus_dma_tag_create(sc->sc_pdmatag, 1, 0,
180 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL, MCLBYTES,
181 	    1, MCLBYTES, BUS_DMA_ALLOCNOW, NULL, NULL, &sc->sc_rdmatag);
182 	if (error)
183 		goto fail_ptag;
184 
185 	error = bus_dma_tag_create(sc->sc_pdmatag, 1, 0,
186 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
187 	    MCLBYTES * GEM_NTXSEGS, GEM_NTXSEGS, MCLBYTES,
188 	    BUS_DMA_ALLOCNOW, NULL, NULL, &sc->sc_tdmatag);
189 	if (error)
190 		goto fail_rtag;
191 
192 	error = bus_dma_tag_create(sc->sc_pdmatag, PAGE_SIZE, 0,
193 	    BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
194 	    sizeof(struct gem_control_data), 1,
195 	    sizeof(struct gem_control_data), 0,
196 	    NULL, NULL, &sc->sc_cdmatag);
197 	if (error)
198 		goto fail_ttag;
199 
200 	/*
201 	 * Allocate the control data structures, and create and load the
202 	 * DMA map for it.
203 	 */
204 	if ((error = bus_dmamem_alloc(sc->sc_cdmatag,
205 	    (void **)&sc->sc_control_data,
206 	    BUS_DMA_WAITOK | BUS_DMA_COHERENT | BUS_DMA_ZERO,
207 	    &sc->sc_cddmamap))) {
208 		device_printf(sc->sc_dev, "unable to allocate control data,"
209 		    " error = %d\n", error);
210 		goto fail_ctag;
211 	}
212 
213 	sc->sc_cddma = 0;
214 	if ((error = bus_dmamap_load(sc->sc_cdmatag, sc->sc_cddmamap,
215 	    sc->sc_control_data, sizeof(struct gem_control_data),
216 	    gem_cddma_callback, sc, 0)) != 0 || sc->sc_cddma == 0) {
217 		device_printf(sc->sc_dev, "unable to load control data DMA "
218 		    "map, error = %d\n", error);
219 		goto fail_cmem;
220 	}
221 
222 	/*
223 	 * Initialize the transmit job descriptors.
224 	 */
225 	STAILQ_INIT(&sc->sc_txfreeq);
226 	STAILQ_INIT(&sc->sc_txdirtyq);
227 
228 	/*
229 	 * Create the transmit buffer DMA maps.
230 	 */
231 	error = ENOMEM;
232 	for (i = 0; i < GEM_TXQUEUELEN; i++) {
233 		struct gem_txsoft *txs;
234 
235 		txs = &sc->sc_txsoft[i];
236 		txs->txs_mbuf = NULL;
237 		txs->txs_ndescs = 0;
238 		if ((error = bus_dmamap_create(sc->sc_tdmatag, 0,
239 		    &txs->txs_dmamap)) != 0) {
240 			device_printf(sc->sc_dev, "unable to create tx DMA map "
241 			    "%d, error = %d\n", i, error);
242 			goto fail_txd;
243 		}
244 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
245 	}
246 
247 	/*
248 	 * Create the receive buffer DMA maps.
249 	 */
250 	for (i = 0; i < GEM_NRXDESC; i++) {
251 		if ((error = bus_dmamap_create(sc->sc_rdmatag, 0,
252 		    &sc->sc_rxsoft[i].rxs_dmamap)) != 0) {
253 			device_printf(sc->sc_dev, "unable to create rx DMA map "
254 			    "%d, error = %d\n", i, error);
255 			goto fail_rxd;
256 		}
257 		sc->sc_rxsoft[i].rxs_mbuf = NULL;
258 	}
259 
260 	gem_mifinit(sc);
261 
262 	if ((error = mii_phy_probe(sc->sc_dev, &sc->sc_miibus, gem_mediachange,
263 	    gem_mediastatus)) != 0) {
264 		device_printf(sc->sc_dev, "phy probe failed: %d\n", error);
265 		goto fail_rxd;
266 	}
267 	sc->sc_mii = device_get_softc(sc->sc_miibus);
268 
269 	/*
270 	 * From this point forward, the attachment cannot fail.  A failure
271 	 * before this point releases all resources that may have been
272 	 * allocated.
273 	 */
274 
275 	/* Get RX FIFO size */
276 	sc->sc_rxfifosize = 64 *
277 	    bus_read_4(sc->sc_res[0], GEM_RX_FIFO_SIZE);
278 
279 	/* Get TX FIFO size */
280 	v = bus_read_4(sc->sc_res[0], GEM_TX_FIFO_SIZE);
281 	device_printf(sc->sc_dev, "%ukB RX FIFO, %ukB TX FIFO\n",
282 	    sc->sc_rxfifosize / 1024, v / 16);
283 
284 	sc->sc_csum_features = GEM_CSUM_FEATURES;
285 	/* Initialize ifnet structure. */
286 	ifp->if_softc = sc;
287 	if_initname(ifp, device_get_name(sc->sc_dev),
288 	    device_get_unit(sc->sc_dev));
289 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
290 	ifp->if_start = gem_start;
291 	ifp->if_ioctl = gem_ioctl;
292 	ifp->if_init = gem_init;
293 	IFQ_SET_MAXLEN(&ifp->if_snd, GEM_TXQUEUELEN);
294 	ifp->if_snd.ifq_drv_maxlen = GEM_TXQUEUELEN;
295 	IFQ_SET_READY(&ifp->if_snd);
296 	/*
297 	 * Walk along the list of attached MII devices and
298 	 * establish an `MII instance' to `phy number'
299 	 * mapping. We'll use this mapping in media change
300 	 * requests to determine which phy to use to program
301 	 * the MIF configuration register.
302 	 */
303 	for (child = LIST_FIRST(&sc->sc_mii->mii_phys); child != NULL;
304 	     child = LIST_NEXT(child, mii_list)) {
305 		/*
306 		 * Note: we support just two PHYs: the built-in
307 		 * internal device and an external on the MII
308 		 * connector.
309 		 */
310 		if (child->mii_phy > 1 || child->mii_inst > 1) {
311 			device_printf(sc->sc_dev, "cannot accomodate "
312 			    "MII device %s at phy %d, instance %d\n",
313 			    device_get_name(child->mii_dev),
314 			    child->mii_phy, child->mii_inst);
315 			continue;
316 		}
317 
318 		sc->sc_phys[child->mii_inst] = child->mii_phy;
319 	}
320 
321 	/*
322 	 * Now select and activate the PHY we will use.
323 	 *
324 	 * The order of preference is External (MDI1),
325 	 * Internal (MDI0), Serial Link (no MII).
326 	 */
327 	if (sc->sc_phys[1]) {
328 #ifdef GEM_DEBUG
329 		printf("using external phy\n");
330 #endif
331 		sc->sc_mif_config |= GEM_MIF_CONFIG_PHY_SEL;
332 	} else {
333 #ifdef GEM_DEBUG
334 		printf("using internal phy\n");
335 #endif
336 		sc->sc_mif_config &= ~GEM_MIF_CONFIG_PHY_SEL;
337 	}
338 	bus_write_4(sc->sc_res[0], GEM_MIF_CONFIG,
339 	    sc->sc_mif_config);
340 	/* Attach the interface. */
341 	ether_ifattach(ifp, sc->sc_enaddr);
342 
343 #ifdef notyet
344 	/*
345 	 * Add a suspend hook to make sure we come back up after a
346 	 * resume.
347 	 */
348 	sc->sc_powerhook = powerhook_establish(gem_power, sc);
349 	if (sc->sc_powerhook == NULL)
350 		device_printf(sc->sc_dev, "WARNING: unable to establish power "
351 		    "hook\n");
352 #endif
353 
354 	/*
355 	 * Tell the upper layer(s) we support long frames/checksum offloads.
356 	 */
357 	ifp->if_data.ifi_hdrlen = sizeof(struct ether_vlan_header);
358 	ifp->if_capabilities |= IFCAP_VLAN_MTU | IFCAP_HWCSUM;
359 	ifp->if_hwassist |= sc->sc_csum_features;
360 	ifp->if_capenable |= IFCAP_VLAN_MTU | IFCAP_HWCSUM;
361 
362 	return (0);
363 
364 	/*
365 	 * Free any resources we've allocated during the failed attach
366 	 * attempt.  Do this in reverse order and fall through.
367 	 */
368 fail_rxd:
369 	for (i = 0; i < GEM_NRXDESC; i++) {
370 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
371 			bus_dmamap_destroy(sc->sc_rdmatag,
372 			    sc->sc_rxsoft[i].rxs_dmamap);
373 	}
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 	}
380 	bus_dmamap_unload(sc->sc_cdmatag, sc->sc_cddmamap);
381 fail_cmem:
382 	bus_dmamem_free(sc->sc_cdmatag, sc->sc_control_data,
383 	    sc->sc_cddmamap);
384 fail_ctag:
385 	bus_dma_tag_destroy(sc->sc_cdmatag);
386 fail_ttag:
387 	bus_dma_tag_destroy(sc->sc_tdmatag);
388 fail_rtag:
389 	bus_dma_tag_destroy(sc->sc_rdmatag);
390 fail_ptag:
391 	bus_dma_tag_destroy(sc->sc_pdmatag);
392 fail_ifnet:
393 	if_free(ifp);
394 	return (error);
395 }
396 
397 void
398 gem_detach(sc)
399 	struct gem_softc *sc;
400 {
401 	struct ifnet *ifp = sc->sc_ifp;
402 	int i;
403 
404 	GEM_LOCK(sc);
405 	gem_stop(ifp, 1);
406 	GEM_UNLOCK(sc);
407 	callout_drain(&sc->sc_tick_ch);
408 #ifdef GEM_RINT_TIMEOUT
409 	callout_drain(&sc->sc_rx_ch);
410 #endif
411 	ether_ifdetach(ifp);
412 	if_free(ifp);
413 	device_delete_child(sc->sc_dev, sc->sc_miibus);
414 
415 	for (i = 0; i < GEM_NRXDESC; i++) {
416 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
417 			bus_dmamap_destroy(sc->sc_rdmatag,
418 			    sc->sc_rxsoft[i].rxs_dmamap);
419 	}
420 	for (i = 0; i < GEM_TXQUEUELEN; i++) {
421 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
422 			bus_dmamap_destroy(sc->sc_tdmatag,
423 			    sc->sc_txsoft[i].txs_dmamap);
424 	}
425 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD);
426 	GEM_CDSYNC(sc, 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(sc)
438 	struct gem_softc *sc;
439 {
440 	struct ifnet *ifp = sc->sc_ifp;
441 
442 	GEM_LOCK(sc);
443 	gem_stop(ifp, 0);
444 	GEM_UNLOCK(sc);
445 }
446 
447 void
448 gem_resume(sc)
449 	struct gem_softc *sc;
450 {
451 	struct ifnet *ifp = sc->sc_ifp;
452 
453 	GEM_LOCK(sc);
454 	/*
455 	 * On resume all registers have to be initialized again like
456 	 * after power-on.
457 	 */
458 	sc->sc_inited = 0;
459 	if (ifp->if_flags & IFF_UP)
460 		gem_init_locked(sc);
461 	GEM_UNLOCK(sc);
462 }
463 
464 static __inline void
465 gem_txcksum(struct gem_softc *sc, struct mbuf *m, uint64_t *cflags)
466 {
467 	struct ip *ip;
468 	uint64_t offset, offset2;
469 	char *p;
470 
471 	offset = sizeof(struct ip) + ETHER_HDR_LEN;
472 	for(; m && m->m_len == 0; m = m->m_next)
473 		;
474 	if (m == NULL || m->m_len < ETHER_HDR_LEN) {
475 		device_printf(sc->sc_dev, "%s: m_len < ETHER_HDR_LEN\n",
476 		    __func__);
477 		/* checksum will be corrupted */
478 		goto sendit;
479 	}
480 	if (m->m_len < ETHER_HDR_LEN + sizeof(uint32_t)) {
481 		if (m->m_len != ETHER_HDR_LEN) {
482 			device_printf(sc->sc_dev,
483 			    "%s: m_len != ETHER_HDR_LEN\n", __func__);
484 			/* checksum will be corrupted */
485 			goto sendit;
486 		}
487 		for(m = m->m_next; m && m->m_len == 0; m = m->m_next)
488 			;
489 		if (m == NULL) {
490 			/* checksum will be corrupted */
491 			goto sendit;
492 		}
493 		ip = mtod(m, struct ip *);
494 	} else {
495 		p = mtod(m, uint8_t *);
496 		p += ETHER_HDR_LEN;
497 		ip = (struct ip *)p;
498 	}
499 	offset = (ip->ip_hl << 2) + ETHER_HDR_LEN;
500 
501 sendit:
502 	offset2 = m->m_pkthdr.csum_data;
503 	*cflags = offset << GEM_TD_CXSUM_STARTSHFT;
504 	*cflags |= ((offset + offset2) << GEM_TD_CXSUM_STUFFSHFT);
505 	*cflags |= GEM_TD_CXSUM_ENABLE;
506 }
507 
508 static __inline void
509 gem_rxcksum(struct mbuf *m, uint64_t flags)
510 {
511 	struct ether_header *eh;
512 	struct ip *ip;
513 	struct udphdr *uh;
514 	int32_t hlen, len, pktlen;
515 	uint16_t cksum, *opts;
516 	uint32_t temp32;
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;	/* can't 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(xsc, segs, nsegs, error)
572 	void *xsc;
573 	bus_dma_segment_t *segs;
574 	int nsegs;
575 	int error;
576 {
577 	struct gem_softc *sc = (struct gem_softc *)xsc;
578 
579 	if (error != 0)
580 		return;
581 	if (nsegs != 1) {
582 		/* can't happen... */
583 		panic("gem_cddma_callback: bad control buffer segment count");
584 	}
585 	sc->sc_cddma = segs[0].ds_addr;
586 }
587 
588 static void
589 gem_tick(arg)
590 	void *arg;
591 {
592 	struct gem_softc *sc = arg;
593 	struct ifnet *ifp;
594 
595 	GEM_LOCK_ASSERT(sc, MA_OWNED);
596 
597 	ifp = sc->sc_ifp;
598 	/*
599 	 * Unload collision counters
600 	 */
601 	ifp->if_collisions +=
602 	    bus_read_4(sc->sc_res[0], GEM_MAC_NORM_COLL_CNT) +
603 	    bus_read_4(sc->sc_res[0], GEM_MAC_FIRST_COLL_CNT) +
604 	    bus_read_4(sc->sc_res[0], GEM_MAC_EXCESS_COLL_CNT) +
605 	    bus_read_4(sc->sc_res[0], GEM_MAC_LATE_COLL_CNT);
606 
607 	/*
608 	 * then clear the hardware counters.
609 	 */
610 	bus_write_4(sc->sc_res[0], GEM_MAC_NORM_COLL_CNT, 0);
611 	bus_write_4(sc->sc_res[0], GEM_MAC_FIRST_COLL_CNT, 0);
612 	bus_write_4(sc->sc_res[0], GEM_MAC_EXCESS_COLL_CNT, 0);
613 	bus_write_4(sc->sc_res[0], GEM_MAC_LATE_COLL_CNT, 0);
614 
615 	mii_tick(sc->sc_mii);
616 
617 	if (gem_watchdog(sc) == EJUSTRETURN)
618 		return;
619 
620 	callout_reset(&sc->sc_tick_ch, hz, gem_tick, sc);
621 }
622 
623 static int
624 gem_bitwait(sc, r, clr, set)
625 	struct gem_softc *sc;
626 	bus_addr_t r;
627 	u_int32_t clr;
628 	u_int32_t set;
629 {
630 	int i;
631 	u_int32_t reg;
632 
633 	for (i = TRIES; i--; DELAY(100)) {
634 		reg = bus_read_4(sc->sc_res[0], r);
635 		if ((reg & clr) == 0 && (reg & set) == set)
636 			return (1);
637 	}
638 	return (0);
639 }
640 
641 void
642 gem_reset(sc)
643 	struct gem_softc *sc;
644 {
645 
646 #ifdef GEM_DEBUG
647 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
648 #endif
649 	gem_reset_rx(sc);
650 	gem_reset_tx(sc);
651 
652 	/* Do a full reset */
653 	bus_write_4(sc->sc_res[0], GEM_RESET, GEM_RESET_RX | GEM_RESET_TX);
654 	if (!gem_bitwait(sc, GEM_RESET, GEM_RESET_RX | GEM_RESET_TX, 0))
655 		device_printf(sc->sc_dev, "cannot reset device\n");
656 }
657 
658 
659 /*
660  * gem_rxdrain:
661  *
662  *	Drain the receive queue.
663  */
664 static void
665 gem_rxdrain(sc)
666 	struct gem_softc *sc;
667 {
668 	struct gem_rxsoft *rxs;
669 	int i;
670 
671 	for (i = 0; i < GEM_NRXDESC; i++) {
672 		rxs = &sc->sc_rxsoft[i];
673 		if (rxs->rxs_mbuf != NULL) {
674 			bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
675 			    BUS_DMASYNC_POSTREAD);
676 			bus_dmamap_unload(sc->sc_rdmatag, rxs->rxs_dmamap);
677 			m_freem(rxs->rxs_mbuf);
678 			rxs->rxs_mbuf = NULL;
679 		}
680 	}
681 }
682 
683 /*
684  * Reset the whole thing.
685  */
686 static void
687 gem_stop(ifp, disable)
688 	struct ifnet *ifp;
689 	int disable;
690 {
691 	struct gem_softc *sc = (struct gem_softc *)ifp->if_softc;
692 	struct gem_txsoft *txs;
693 
694 #ifdef GEM_DEBUG
695 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
696 #endif
697 
698 	callout_stop(&sc->sc_tick_ch);
699 #ifdef GEM_RINT_TIMEOUT
700 	callout_stop(&sc->sc_rx_ch);
701 #endif
702 
703 	/* XXX - Should we reset these instead? */
704 	gem_disable_tx(sc);
705 	gem_disable_rx(sc);
706 
707 	/*
708 	 * Release any queued transmit buffers.
709 	 */
710 	while ((txs = STAILQ_FIRST(&sc->sc_txdirtyq)) != NULL) {
711 		STAILQ_REMOVE_HEAD(&sc->sc_txdirtyq, txs_q);
712 		if (txs->txs_ndescs != 0) {
713 			bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
714 			    BUS_DMASYNC_POSTWRITE);
715 			bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
716 			if (txs->txs_mbuf != NULL) {
717 				m_freem(txs->txs_mbuf);
718 				txs->txs_mbuf = NULL;
719 			}
720 		}
721 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
722 	}
723 
724 	if (disable)
725 		gem_rxdrain(sc);
726 
727 	/*
728 	 * Mark the interface down and cancel the watchdog timer.
729 	 */
730 	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
731 	sc->sc_wdog_timer = 0;
732 }
733 
734 /*
735  * Reset the receiver
736  */
737 int
738 gem_reset_rx(sc)
739 	struct gem_softc *sc;
740 {
741 
742 	/*
743 	 * Resetting while DMA is in progress can cause a bus hang, so we
744 	 * disable DMA first.
745 	 */
746 	gem_disable_rx(sc);
747 	bus_write_4(sc->sc_res[0], GEM_RX_CONFIG, 0);
748 	/* Wait till it finishes */
749 	if (!gem_bitwait(sc, GEM_RX_CONFIG, 1, 0))
750 		device_printf(sc->sc_dev, "cannot disable read dma\n");
751 
752 	/* Wait 5ms extra. */
753 	DELAY(5000);
754 
755 	/* Finally, reset the ERX */
756 	bus_write_4(sc->sc_res[0], GEM_RESET, GEM_RESET_RX);
757 	/* Wait till it finishes */
758 	if (!gem_bitwait(sc, GEM_RESET, GEM_RESET_RX, 0)) {
759 		device_printf(sc->sc_dev, "cannot reset receiver\n");
760 		return (1);
761 	}
762 	return (0);
763 }
764 
765 
766 /*
767  * Reset the transmitter
768  */
769 static int
770 gem_reset_tx(sc)
771 	struct gem_softc *sc;
772 {
773 	int i;
774 
775 	/*
776 	 * Resetting while DMA is in progress can cause a bus hang, so we
777 	 * disable DMA first.
778 	 */
779 	gem_disable_tx(sc);
780 	bus_write_4(sc->sc_res[0], GEM_TX_CONFIG, 0);
781 	/* Wait till it finishes */
782 	if (!gem_bitwait(sc, GEM_TX_CONFIG, 1, 0))
783 		device_printf(sc->sc_dev, "cannot disable read dma\n");
784 
785 	/* Wait 5ms extra. */
786 	DELAY(5000);
787 
788 	/* Finally, reset the ETX */
789 	bus_write_4(sc->sc_res[0], GEM_RESET, GEM_RESET_TX);
790 	/* Wait till it finishes */
791 	for (i = TRIES; i--; DELAY(100))
792 		if ((bus_read_4(sc->sc_res[0], GEM_RESET) & GEM_RESET_TX) == 0)
793 			break;
794 	if (!gem_bitwait(sc, GEM_RESET, GEM_RESET_TX, 0)) {
795 		device_printf(sc->sc_dev, "cannot reset receiver\n");
796 		return (1);
797 	}
798 	return (0);
799 }
800 
801 /*
802  * disable receiver.
803  */
804 static int
805 gem_disable_rx(sc)
806 	struct gem_softc *sc;
807 {
808 	u_int32_t cfg;
809 
810 	/* Flip the enable bit */
811 	cfg = bus_read_4(sc->sc_res[0], GEM_MAC_RX_CONFIG);
812 	cfg &= ~GEM_MAC_RX_ENABLE;
813 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CONFIG, cfg);
814 
815 	/* Wait for it to finish */
816 	return (gem_bitwait(sc, GEM_MAC_RX_CONFIG, GEM_MAC_RX_ENABLE, 0));
817 }
818 
819 /*
820  * disable transmitter.
821  */
822 static int
823 gem_disable_tx(sc)
824 	struct gem_softc *sc;
825 {
826 	u_int32_t cfg;
827 
828 	/* Flip the enable bit */
829 	cfg = bus_read_4(sc->sc_res[0], GEM_MAC_TX_CONFIG);
830 	cfg &= ~GEM_MAC_TX_ENABLE;
831 	bus_write_4(sc->sc_res[0], GEM_MAC_TX_CONFIG, cfg);
832 
833 	/* Wait for it to finish */
834 	return (gem_bitwait(sc, GEM_MAC_TX_CONFIG, GEM_MAC_TX_ENABLE, 0));
835 }
836 
837 /*
838  * Initialize interface.
839  */
840 static int
841 gem_meminit(sc)
842 	struct gem_softc *sc;
843 {
844 	struct gem_rxsoft *rxs;
845 	int i, error;
846 
847 	/*
848 	 * Initialize the transmit descriptor ring.
849 	 */
850 	for (i = 0; i < GEM_NTXDESC; i++) {
851 		sc->sc_txdescs[i].gd_flags = 0;
852 		sc->sc_txdescs[i].gd_addr = 0;
853 	}
854 	sc->sc_txfree = GEM_MAXTXFREE;
855 	sc->sc_txnext = 0;
856 	sc->sc_txwin = 0;
857 
858 	/*
859 	 * Initialize the receive descriptor and receive job
860 	 * descriptor rings.
861 	 */
862 	for (i = 0; i < GEM_NRXDESC; i++) {
863 		rxs = &sc->sc_rxsoft[i];
864 		if (rxs->rxs_mbuf == NULL) {
865 			if ((error = gem_add_rxbuf(sc, i)) != 0) {
866 				device_printf(sc->sc_dev, "unable to "
867 				    "allocate or map rx buffer %d, error = "
868 				    "%d\n", i, error);
869 				/*
870 				 * XXX Should attempt to run with fewer receive
871 				 * XXX buffers instead of just failing.
872 				 */
873 				gem_rxdrain(sc);
874 				return (1);
875 			}
876 		} else
877 			GEM_INIT_RXDESC(sc, i);
878 	}
879 	sc->sc_rxptr = 0;
880 	GEM_CDSYNC(sc, BUS_DMASYNC_PREWRITE);
881 	GEM_CDSYNC(sc, BUS_DMASYNC_PREREAD);
882 
883 	return (0);
884 }
885 
886 static int
887 gem_ringsize(sz)
888 	int sz;
889 {
890 	int v = 0;
891 
892 	switch (sz) {
893 	case 32:
894 		v = GEM_RING_SZ_32;
895 		break;
896 	case 64:
897 		v = GEM_RING_SZ_64;
898 		break;
899 	case 128:
900 		v = GEM_RING_SZ_128;
901 		break;
902 	case 256:
903 		v = GEM_RING_SZ_256;
904 		break;
905 	case 512:
906 		v = GEM_RING_SZ_512;
907 		break;
908 	case 1024:
909 		v = GEM_RING_SZ_1024;
910 		break;
911 	case 2048:
912 		v = GEM_RING_SZ_2048;
913 		break;
914 	case 4096:
915 		v = GEM_RING_SZ_4096;
916 		break;
917 	case 8192:
918 		v = GEM_RING_SZ_8192;
919 		break;
920 	default:
921 		printf("gem: invalid Receive Descriptor ring size\n");
922 		break;
923 	}
924 	return (v);
925 }
926 
927 static void
928 gem_init(xsc)
929 	void *xsc;
930 {
931 	struct gem_softc *sc = (struct gem_softc *)xsc;
932 
933 	GEM_LOCK(sc);
934 	gem_init_locked(sc);
935 	GEM_UNLOCK(sc);
936 }
937 
938 /*
939  * Initialization of interface; set up initialization block
940  * and transmit/receive descriptor rings.
941  */
942 static void
943 gem_init_locked(sc)
944 	struct gem_softc *sc;
945 {
946 	struct ifnet *ifp = sc->sc_ifp;
947 	u_int32_t v;
948 
949 	GEM_LOCK_ASSERT(sc, MA_OWNED);
950 
951 #ifdef GEM_DEBUG
952 	CTR2(KTR_GEM, "%s: %s: calling stop", device_get_name(sc->sc_dev),
953 	    __func__);
954 #endif
955 	/*
956 	 * Initialization sequence. The numbered steps below correspond
957 	 * to the sequence outlined in section 6.3.5.1 in the Ethernet
958 	 * Channel Engine manual (part of the PCIO manual).
959 	 * See also the STP2002-STQ document from Sun Microsystems.
960 	 */
961 
962 	/* step 1 & 2. Reset the Ethernet Channel */
963 	gem_stop(sc->sc_ifp, 0);
964 	gem_reset(sc);
965 #ifdef GEM_DEBUG
966 	CTR2(KTR_GEM, "%s: %s: restarting", device_get_name(sc->sc_dev),
967 	    __func__);
968 #endif
969 
970 	/* Re-initialize the MIF */
971 	gem_mifinit(sc);
972 
973 	/* step 3. Setup data structures in host memory */
974 	gem_meminit(sc);
975 
976 	/* step 4. TX MAC registers & counters */
977 	gem_init_regs(sc);
978 
979 	/* step 5. RX MAC registers & counters */
980 	gem_setladrf(sc);
981 
982 	/* step 6 & 7. Program Descriptor Ring Base Addresses */
983 	/* NOTE: we use only 32-bit DMA addresses here. */
984 	bus_write_4(sc->sc_res[0], GEM_TX_RING_PTR_HI, 0);
985 	bus_write_4(sc->sc_res[0], GEM_TX_RING_PTR_LO, GEM_CDTXADDR(sc, 0));
986 
987 	bus_write_4(sc->sc_res[0], GEM_RX_RING_PTR_HI, 0);
988 	bus_write_4(sc->sc_res[0], GEM_RX_RING_PTR_LO, GEM_CDRXADDR(sc, 0));
989 #ifdef GEM_DEBUG
990 	CTR3(KTR_GEM, "loading rx ring %lx, tx ring %lx, cddma %lx",
991 	    GEM_CDRXADDR(sc, 0), GEM_CDTXADDR(sc, 0), sc->sc_cddma);
992 #endif
993 
994 	/* step 8. Global Configuration & Interrupt Mask */
995 	bus_write_4(sc->sc_res[0], GEM_INTMASK,
996 		      ~(GEM_INTR_TX_INTME|
997 			GEM_INTR_TX_EMPTY|
998 			GEM_INTR_RX_DONE|GEM_INTR_RX_NOBUF|
999 			GEM_INTR_RX_TAG_ERR|GEM_INTR_PCS|
1000 			GEM_INTR_MAC_CONTROL|GEM_INTR_MIF|
1001 			GEM_INTR_BERR));
1002 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_MASK,
1003 			GEM_MAC_RX_DONE|GEM_MAC_RX_FRAME_CNT);
1004 	bus_write_4(sc->sc_res[0], GEM_MAC_TX_MASK, 0xffff); /* XXXX */
1005 	bus_write_4(sc->sc_res[0], GEM_MAC_CONTROL_MASK, 0); /* XXXX */
1006 
1007 	/* step 9. ETX Configuration: use mostly default values */
1008 
1009 	/* Enable DMA */
1010 	v = gem_ringsize(GEM_NTXDESC /*XXX*/);
1011 	bus_write_4(sc->sc_res[0], GEM_TX_CONFIG,
1012 		v|GEM_TX_CONFIG_TXDMA_EN|
1013 		((0x400<<10)&GEM_TX_CONFIG_TXFIFO_TH));
1014 
1015 	/* step 10. ERX Configuration */
1016 
1017 	/* Encode Receive Descriptor ring size: four possible values */
1018 	v = gem_ringsize(GEM_NRXDESC /*XXX*/);
1019 	/* Rx TCP/UDP checksum offset */
1020 	v |= ((ETHER_HDR_LEN + sizeof(struct ip)) <<
1021 	    GEM_RX_CONFIG_CXM_START_SHFT);
1022 
1023 	/* Enable DMA */
1024 	bus_write_4(sc->sc_res[0], GEM_RX_CONFIG,
1025 		v|(GEM_THRSH_1024<<GEM_RX_CONFIG_FIFO_THRS_SHIFT)|
1026 		(2<<GEM_RX_CONFIG_FBOFF_SHFT)|GEM_RX_CONFIG_RXDMA_EN);
1027 	/*
1028 	 * The following value is for an OFF Threshold of about 3/4 full
1029 	 * and an ON Threshold of 1/4 full.
1030 	 */
1031 	bus_write_4(sc->sc_res[0], GEM_RX_PAUSE_THRESH,
1032 	    (3 * sc->sc_rxfifosize / 256) |
1033 	    (   (sc->sc_rxfifosize / 256) << 12));
1034 	bus_write_4(sc->sc_res[0], GEM_RX_BLANKING, (6<<12)|6);
1035 
1036 	/* step 11. Configure Media */
1037 	mii_mediachg(sc->sc_mii);
1038 
1039 	/* step 12. RX_MAC Configuration Register */
1040 	v = bus_read_4(sc->sc_res[0], GEM_MAC_RX_CONFIG);
1041 	v |= GEM_MAC_RX_ENABLE | GEM_MAC_RX_STRIP_CRC;
1042 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CONFIG, v);
1043 
1044 	/* step 14. Issue Transmit Pending command */
1045 
1046 	/* step 15.  Give the reciever a swift kick */
1047 	bus_write_4(sc->sc_res[0], GEM_RX_KICK, GEM_NRXDESC-4);
1048 
1049 	/* Start the one second timer. */
1050 	sc->sc_wdog_timer = 0;
1051 	callout_reset(&sc->sc_tick_ch, hz, gem_tick, sc);
1052 
1053 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
1054 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1055 	sc->sc_ifflags = ifp->if_flags;
1056 }
1057 
1058 /*
1059  * It's copy of ath_defrag(ath(4)).
1060  *
1061  * Defragment an mbuf chain, returning at most maxfrags separate
1062  * mbufs+clusters.  If this is not possible NULL is returned and
1063  * the original mbuf chain is left in it's present (potentially
1064  * modified) state.  We use two techniques: collapsing consecutive
1065  * mbufs and replacing consecutive mbufs by a cluster.
1066  */
1067 static struct mbuf *
1068 gem_defrag(m0, how, maxfrags)
1069 	struct mbuf *m0;
1070 	int how;
1071 	int maxfrags;
1072 {
1073 	struct mbuf *m, *n, *n2, **prev;
1074 	u_int curfrags;
1075 
1076 	/*
1077 	 * Calculate the current number of frags.
1078 	 */
1079 	curfrags = 0;
1080 	for (m = m0; m != NULL; m = m->m_next)
1081 		curfrags++;
1082 	/*
1083 	 * First, try to collapse mbufs.  Note that we always collapse
1084 	 * towards the front so we don't need to deal with moving the
1085 	 * pkthdr.  This may be suboptimal if the first mbuf has much
1086 	 * less data than the following.
1087 	 */
1088 	m = m0;
1089 again:
1090 	for (;;) {
1091 		n = m->m_next;
1092 		if (n == NULL)
1093 			break;
1094 		if ((m->m_flags & M_RDONLY) == 0 &&
1095 		    n->m_len < M_TRAILINGSPACE(m)) {
1096 			bcopy(mtod(n, void *), mtod(m, char *) + m->m_len,
1097 				n->m_len);
1098 			m->m_len += n->m_len;
1099 			m->m_next = n->m_next;
1100 			m_free(n);
1101 			if (--curfrags <= maxfrags)
1102 				return (m0);
1103 		} else
1104 			m = n;
1105 	}
1106 	KASSERT(maxfrags > 1,
1107 		("maxfrags %u, but normal collapse failed", maxfrags));
1108 	/*
1109 	 * Collapse consecutive mbufs to a cluster.
1110 	 */
1111 	prev = &m0->m_next;		/* NB: not the first mbuf */
1112 	while ((n = *prev) != NULL) {
1113 		if ((n2 = n->m_next) != NULL &&
1114 		    n->m_len + n2->m_len < MCLBYTES) {
1115 			m = m_getcl(how, MT_DATA, 0);
1116 			if (m == NULL)
1117 				goto bad;
1118 			bcopy(mtod(n, void *), mtod(m, void *), n->m_len);
1119 			bcopy(mtod(n2, void *), mtod(m, char *) + n->m_len,
1120 				n2->m_len);
1121 			m->m_len = n->m_len + n2->m_len;
1122 			m->m_next = n2->m_next;
1123 			*prev = m;
1124 			m_free(n);
1125 			m_free(n2);
1126 			if (--curfrags <= maxfrags)	/* +1 cl -2 mbufs */
1127 				return m0;
1128 			/*
1129 			 * Still not there, try the normal collapse
1130 			 * again before we allocate another cluster.
1131 			 */
1132 			goto again;
1133 		}
1134 		prev = &n->m_next;
1135 	}
1136 	/*
1137 	 * No place where we can collapse to a cluster; punt.
1138 	 * This can occur if, for example, you request 2 frags
1139 	 * but the packet requires that both be clusters (we
1140 	 * never reallocate the first mbuf to avoid moving the
1141 	 * packet header).
1142 	 */
1143 bad:
1144 	return (NULL);
1145 }
1146 
1147 static int
1148 gem_load_txmbuf(sc, m_head)
1149 	struct gem_softc *sc;
1150 	struct mbuf **m_head;
1151 {
1152 	struct gem_txsoft *txs;
1153 	bus_dma_segment_t txsegs[GEM_NTXSEGS];
1154 	struct mbuf *m;
1155 	uint64_t flags, cflags;
1156 	int error, nexttx, nsegs, seg;
1157 
1158 	/* Get a work queue entry. */
1159 	if ((txs = STAILQ_FIRST(&sc->sc_txfreeq)) == NULL) {
1160 		/* Ran out of descriptors. */
1161 		return (ENOBUFS);
1162 	}
1163 	error = bus_dmamap_load_mbuf_sg(sc->sc_tdmatag, txs->txs_dmamap,
1164 	    *m_head, txsegs, &nsegs, BUS_DMA_NOWAIT);
1165 	if (error == EFBIG) {
1166 		m = gem_defrag(*m_head, M_DONTWAIT, GEM_NTXSEGS);
1167 		if (m == NULL) {
1168 			m_freem(*m_head);
1169 			*m_head = NULL;
1170 			return (ENOBUFS);
1171 		}
1172 		*m_head = m;
1173 		error = bus_dmamap_load_mbuf_sg(sc->sc_tdmatag, txs->txs_dmamap,
1174 		    *m_head, txsegs, &nsegs, BUS_DMA_NOWAIT);
1175 		if (error != 0) {
1176 			m_freem(*m_head);
1177 			*m_head = NULL;
1178 			return (error);
1179 		}
1180 	} else if (error != 0)
1181 		return (error);
1182 	if (nsegs == 0) {
1183 		m_freem(*m_head);
1184 		*m_head = NULL;
1185 		return (EIO);
1186 	}
1187 
1188 	/*
1189 	 * Ensure we have enough descriptors free to describe
1190 	 * the packet.  Note, we always reserve one descriptor
1191 	 * at the end of the ring as a termination point, to
1192 	 * prevent wrap-around.
1193 	 */
1194 	if (nsegs > sc->sc_txfree - 1) {
1195 		txs->txs_ndescs = 0;
1196 		bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
1197 		return (ENOBUFS);
1198 	}
1199 
1200 	flags = cflags = 0;
1201 	if (((*m_head)->m_pkthdr.csum_flags & sc->sc_csum_features) != 0)
1202 		gem_txcksum(sc, *m_head, &cflags);
1203 
1204 	txs->txs_ndescs = nsegs;
1205 	txs->txs_firstdesc = sc->sc_txnext;
1206 	nexttx = txs->txs_firstdesc;
1207 	for (seg = 0; seg < nsegs; seg++, nexttx = GEM_NEXTTX(nexttx)) {
1208 #ifdef	GEM_DEBUG
1209 		CTR6(KTR_GEM, "%s: mapping seg %d (txd %d), len "
1210 		    "%lx, addr %#lx (%#lx)", __func__, seg, nexttx,
1211 		    txsegs[seg].ds_len, txsegs[seg].ds_addr,
1212 		    GEM_DMA_WRITE(sc, txsegs[seg].ds_addr));
1213 #endif
1214 		sc->sc_txdescs[nexttx].gd_addr =
1215 		    GEM_DMA_WRITE(sc, txsegs[seg].ds_addr);
1216 		KASSERT(txsegs[seg].ds_len < GEM_TD_BUFSIZE,
1217 		    ("%s: segment size too large!", __func__));
1218 		flags = txsegs[seg].ds_len & GEM_TD_BUFSIZE;
1219 		sc->sc_txdescs[nexttx].gd_flags =
1220 		    GEM_DMA_WRITE(sc, flags | cflags);
1221 		txs->txs_lastdesc = nexttx;
1222 	}
1223 
1224 	/* set EOP on the last descriptor */
1225 #ifdef	GEM_DEBUG
1226 	CTR3(KTR_GEM, "%s: end of packet at seg %d, tx %d", __func__, seg,
1227 	    nexttx);
1228 #endif
1229 	sc->sc_txdescs[txs->txs_lastdesc].gd_flags |=
1230 	    GEM_DMA_WRITE(sc, GEM_TD_END_OF_PACKET);
1231 
1232 	/* Lastly set SOP on the first descriptor */
1233 #ifdef	GEM_DEBUG
1234 	CTR3(KTR_GEM, "%s: start of packet at seg %d, tx %d", __func__, seg,
1235 	    nexttx);
1236 #endif
1237 	if (++sc->sc_txwin > GEM_NTXSEGS * 2 / 3) {
1238 		sc->sc_txwin = 0;
1239 		flags |= GEM_TD_INTERRUPT_ME;
1240 		sc->sc_txdescs[txs->txs_firstdesc].gd_flags |=
1241 		    GEM_DMA_WRITE(sc, GEM_TD_INTERRUPT_ME |
1242 		    GEM_TD_START_OF_PACKET);
1243 	} else
1244 		sc->sc_txdescs[txs->txs_firstdesc].gd_flags |=
1245 		    GEM_DMA_WRITE(sc, GEM_TD_START_OF_PACKET);
1246 
1247 	/* Sync the DMA map. */
1248 	bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap, BUS_DMASYNC_PREWRITE);
1249 
1250 #ifdef GEM_DEBUG
1251 	CTR4(KTR_GEM, "%s: setting firstdesc=%d, lastdesc=%d, ndescs=%d",
1252 	    __func__, txs->txs_firstdesc, txs->txs_lastdesc, txs->txs_ndescs);
1253 #endif
1254 	STAILQ_REMOVE_HEAD(&sc->sc_txfreeq, txs_q);
1255 	STAILQ_INSERT_TAIL(&sc->sc_txdirtyq, txs, txs_q);
1256 	txs->txs_mbuf = *m_head;
1257 
1258 	sc->sc_txnext = GEM_NEXTTX(txs->txs_lastdesc);
1259 	sc->sc_txfree -= txs->txs_ndescs;
1260 
1261 	return (0);
1262 }
1263 
1264 static void
1265 gem_init_regs(sc)
1266 	struct gem_softc *sc;
1267 {
1268 	const u_char *laddr = IF_LLADDR(sc->sc_ifp);
1269 	u_int32_t v;
1270 
1271 	/* These regs are not cleared on reset */
1272 	if (!sc->sc_inited) {
1273 
1274 		/* Wooo.  Magic values. */
1275 		bus_write_4(sc->sc_res[0], GEM_MAC_IPG0, 0);
1276 		bus_write_4(sc->sc_res[0], GEM_MAC_IPG1, 8);
1277 		bus_write_4(sc->sc_res[0], GEM_MAC_IPG2, 4);
1278 
1279 		bus_write_4(sc->sc_res[0], GEM_MAC_MAC_MIN_FRAME, ETHER_MIN_LEN);
1280 		/* Max frame and max burst size */
1281 		bus_write_4(sc->sc_res[0], GEM_MAC_MAC_MAX_FRAME,
1282 		    (ETHER_MAX_LEN + ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN) |
1283 		    (0x2000 << 16));
1284 
1285 		bus_write_4(sc->sc_res[0], GEM_MAC_PREAMBLE_LEN, 0x7);
1286 		bus_write_4(sc->sc_res[0], GEM_MAC_JAM_SIZE, 0x4);
1287 		bus_write_4(sc->sc_res[0], GEM_MAC_ATTEMPT_LIMIT, 0x10);
1288 		/* Dunno.... */
1289 		bus_write_4(sc->sc_res[0], GEM_MAC_CONTROL_TYPE, 0x8088);
1290 		bus_write_4(sc->sc_res[0], GEM_MAC_RANDOM_SEED,
1291 		    ((laddr[5]<<8)|laddr[4])&0x3ff);
1292 
1293 		/* Secondary MAC addr set to 0:0:0:0:0:0 */
1294 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR3, 0);
1295 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR4, 0);
1296 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR5, 0);
1297 
1298 		/* MAC control addr set to 01:80:c2:00:00:01 */
1299 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR6, 0x0001);
1300 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR7, 0xc200);
1301 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR8, 0x0180);
1302 
1303 		/* MAC filter addr set to 0:0:0:0:0:0 */
1304 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR_FILTER0, 0);
1305 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR_FILTER1, 0);
1306 		bus_write_4(sc->sc_res[0], GEM_MAC_ADDR_FILTER2, 0);
1307 
1308 		bus_write_4(sc->sc_res[0], GEM_MAC_ADR_FLT_MASK1_2, 0);
1309 		bus_write_4(sc->sc_res[0], GEM_MAC_ADR_FLT_MASK0, 0);
1310 
1311 		sc->sc_inited = 1;
1312 	}
1313 
1314 	/* Counters need to be zeroed */
1315 	bus_write_4(sc->sc_res[0], GEM_MAC_NORM_COLL_CNT, 0);
1316 	bus_write_4(sc->sc_res[0], GEM_MAC_FIRST_COLL_CNT, 0);
1317 	bus_write_4(sc->sc_res[0], GEM_MAC_EXCESS_COLL_CNT, 0);
1318 	bus_write_4(sc->sc_res[0], GEM_MAC_LATE_COLL_CNT, 0);
1319 	bus_write_4(sc->sc_res[0], GEM_MAC_DEFER_TMR_CNT, 0);
1320 	bus_write_4(sc->sc_res[0], GEM_MAC_PEAK_ATTEMPTS, 0);
1321 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_FRAME_COUNT, 0);
1322 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_LEN_ERR_CNT, 0);
1323 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_ALIGN_ERR, 0);
1324 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CRC_ERR_CNT, 0);
1325 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CODE_VIOL, 0);
1326 
1327 	/* Un-pause stuff */
1328 #if 0
1329 	bus_write_4(sc->sc_res[0], GEM_MAC_SEND_PAUSE_CMD, 0x1BF0);
1330 #else
1331 	bus_write_4(sc->sc_res[0], GEM_MAC_SEND_PAUSE_CMD, 0);
1332 #endif
1333 
1334 	/*
1335 	 * Set the station address.
1336 	 */
1337 	bus_write_4(sc->sc_res[0], GEM_MAC_ADDR0, (laddr[4]<<8)|laddr[5]);
1338 	bus_write_4(sc->sc_res[0], GEM_MAC_ADDR1, (laddr[2]<<8)|laddr[3]);
1339 	bus_write_4(sc->sc_res[0], GEM_MAC_ADDR2, (laddr[0]<<8)|laddr[1]);
1340 
1341 	/*
1342 	 * Enable MII outputs.  Enable GMII if there is a gigabit PHY.
1343 	 */
1344 	sc->sc_mif_config = bus_read_4(sc->sc_res[0], GEM_MIF_CONFIG);
1345 	v = GEM_MAC_XIF_TX_MII_ENA;
1346 	if (sc->sc_mif_config & GEM_MIF_CONFIG_MDI1) {
1347 		v |= GEM_MAC_XIF_FDPLX_LED;
1348 		if (sc->sc_flags & GEM_GIGABIT)
1349 			v |= GEM_MAC_XIF_GMII_MODE;
1350 	}
1351 	bus_write_4(sc->sc_res[0], GEM_MAC_XIF_CONFIG, v);
1352 }
1353 
1354 static void
1355 gem_start(ifp)
1356 	struct ifnet *ifp;
1357 {
1358 	struct gem_softc *sc = (struct gem_softc *)ifp->if_softc;
1359 
1360 	GEM_LOCK(sc);
1361 	gem_start_locked(ifp);
1362 	GEM_UNLOCK(sc);
1363 }
1364 
1365 static void
1366 gem_start_locked(ifp)
1367 	struct ifnet *ifp;
1368 {
1369 	struct gem_softc *sc = (struct gem_softc *)ifp->if_softc;
1370 	struct mbuf *m;
1371 	int firsttx, ntx = 0, txmfail;
1372 
1373 	if ((ifp->if_drv_flags & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
1374 	    IFF_DRV_RUNNING)
1375 		return;
1376 
1377 	firsttx = sc->sc_txnext;
1378 #ifdef GEM_DEBUG
1379 	CTR4(KTR_GEM, "%s: %s: txfree %d, txnext %d",
1380 	    device_get_name(sc->sc_dev), __func__, sc->sc_txfree, firsttx);
1381 #endif
1382 	for (; !IFQ_DRV_IS_EMPTY(&ifp->if_snd) && sc->sc_txfree > 1;) {
1383 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
1384 		if (m == NULL)
1385 			break;
1386 		txmfail = gem_load_txmbuf(sc, &m);
1387 		if (txmfail != 0) {
1388 			if (m == NULL)
1389 				break;
1390 			ifp->if_drv_flags |= IFF_DRV_OACTIVE;
1391 			IFQ_DRV_PREPEND(&ifp->if_snd, m);
1392 			break;
1393 		}
1394 		ntx++;
1395 		/* Kick the transmitter. */
1396 #ifdef	GEM_DEBUG
1397 		CTR3(KTR_GEM, "%s: %s: kicking tx %d",
1398 		    device_get_name(sc->sc_dev), __func__, sc->sc_txnext);
1399 #endif
1400 		bus_write_4(sc->sc_res[0], GEM_TX_KICK,
1401 			sc->sc_txnext);
1402 
1403 		BPF_MTAP(ifp, m);
1404 	}
1405 
1406 	if (ntx > 0) {
1407 		GEM_CDSYNC(sc, BUS_DMASYNC_PREWRITE);
1408 
1409 #ifdef GEM_DEBUG
1410 		CTR2(KTR_GEM, "%s: packets enqueued, OWN on %d",
1411 		    device_get_name(sc->sc_dev), firsttx);
1412 #endif
1413 
1414 		/* Set a watchdog timer in case the chip flakes out. */
1415 		sc->sc_wdog_timer = 5;
1416 #ifdef GEM_DEBUG
1417 		CTR3(KTR_GEM, "%s: %s: watchdog %d",
1418 		    device_get_name(sc->sc_dev), __func__, sc->sc_wdog_timer);
1419 #endif
1420 	}
1421 }
1422 
1423 /*
1424  * Transmit interrupt.
1425  */
1426 static void
1427 gem_tint(sc)
1428 	struct gem_softc *sc;
1429 {
1430 	struct ifnet *ifp = sc->sc_ifp;
1431 	struct gem_txsoft *txs;
1432 	int txlast;
1433 	int progress = 0;
1434 
1435 
1436 #ifdef GEM_DEBUG
1437 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
1438 #endif
1439 
1440 	/*
1441 	 * Go through our Tx list and free mbufs for those
1442 	 * frames that have been transmitted.
1443 	 */
1444 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD);
1445 	while ((txs = STAILQ_FIRST(&sc->sc_txdirtyq)) != NULL) {
1446 
1447 #ifdef GEM_DEBUG
1448 		if (ifp->if_flags & IFF_DEBUG) {
1449 			int i;
1450 			printf("    txsoft %p transmit chain:\n", txs);
1451 			for (i = txs->txs_firstdesc;; i = GEM_NEXTTX(i)) {
1452 				printf("descriptor %d: ", i);
1453 				printf("gd_flags: 0x%016llx\t", (long long)
1454 					GEM_DMA_READ(sc, sc->sc_txdescs[i].gd_flags));
1455 				printf("gd_addr: 0x%016llx\n", (long long)
1456 					GEM_DMA_READ(sc, sc->sc_txdescs[i].gd_addr));
1457 				if (i == txs->txs_lastdesc)
1458 					break;
1459 			}
1460 		}
1461 #endif
1462 
1463 		/*
1464 		 * In theory, we could harveast some descriptors before
1465 		 * the ring is empty, but that's a bit complicated.
1466 		 *
1467 		 * GEM_TX_COMPLETION points to the last descriptor
1468 		 * processed +1.
1469 		 */
1470 		txlast = bus_read_4(sc->sc_res[0], GEM_TX_COMPLETION);
1471 #ifdef GEM_DEBUG
1472 		CTR4(KTR_GEM, "%s: txs->txs_firstdesc = %d, "
1473 		    "txs->txs_lastdesc = %d, txlast = %d",
1474 		    __func__, txs->txs_firstdesc, txs->txs_lastdesc, txlast);
1475 #endif
1476 		if (txs->txs_firstdesc <= txs->txs_lastdesc) {
1477 			if ((txlast >= txs->txs_firstdesc) &&
1478 				(txlast <= txs->txs_lastdesc))
1479 				break;
1480 		} else {
1481 			/* Ick -- this command wraps */
1482 			if ((txlast >= txs->txs_firstdesc) ||
1483 				(txlast <= txs->txs_lastdesc))
1484 				break;
1485 		}
1486 
1487 #ifdef GEM_DEBUG
1488 		CTR1(KTR_GEM, "%s: releasing a desc", __func__);
1489 #endif
1490 		STAILQ_REMOVE_HEAD(&sc->sc_txdirtyq, txs_q);
1491 
1492 		sc->sc_txfree += txs->txs_ndescs;
1493 
1494 		bus_dmamap_sync(sc->sc_tdmatag, txs->txs_dmamap,
1495 		    BUS_DMASYNC_POSTWRITE);
1496 		bus_dmamap_unload(sc->sc_tdmatag, txs->txs_dmamap);
1497 		if (txs->txs_mbuf != NULL) {
1498 			m_freem(txs->txs_mbuf);
1499 			txs->txs_mbuf = NULL;
1500 		}
1501 
1502 		STAILQ_INSERT_TAIL(&sc->sc_txfreeq, txs, txs_q);
1503 
1504 		ifp->if_opackets++;
1505 		progress = 1;
1506 	}
1507 
1508 #ifdef GEM_DEBUG
1509 	CTR4(KTR_GEM, "%s: GEM_TX_STATE_MACHINE %x "
1510 		"GEM_TX_DATA_PTR %llx "
1511 		"GEM_TX_COMPLETION %x",
1512 		__func__,
1513 		bus_space_read_4(sc->sc_res[0], sc->sc_h, GEM_TX_STATE_MACHINE),
1514 		((long long) bus_4(sc->sc_res[0],
1515 			GEM_TX_DATA_PTR_HI) << 32) |
1516 			     bus_read_4(sc->sc_res[0],
1517 			GEM_TX_DATA_PTR_LO),
1518 		bus_read_4(sc->sc_res[0], GEM_TX_COMPLETION));
1519 #endif
1520 
1521 	if (progress) {
1522 		if (sc->sc_txfree == GEM_NTXDESC - 1)
1523 			sc->sc_txwin = 0;
1524 
1525 		/* Freed some descriptors, so reset IFF_DRV_OACTIVE and restart. */
1526 		ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1527 		sc->sc_wdog_timer = STAILQ_EMPTY(&sc->sc_txdirtyq) ? 0 : 5;
1528 
1529 		if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
1530 		    !IFQ_DRV_IS_EMPTY(&ifp->if_snd))
1531 			gem_start_locked(ifp);
1532 	}
1533 
1534 #ifdef GEM_DEBUG
1535 	CTR3(KTR_GEM, "%s: %s: watchdog %d",
1536 	    device_get_name(sc->sc_dev), __func__, sc->sc_wdog_timer);
1537 #endif
1538 }
1539 
1540 #ifdef GEM_RINT_TIMEOUT
1541 static void
1542 gem_rint_timeout(arg)
1543 	void *arg;
1544 {
1545 	struct gem_softc *sc = (struct gem_softc *)arg;
1546 
1547 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1548 	gem_rint(sc);
1549 }
1550 #endif
1551 
1552 /*
1553  * Receive interrupt.
1554  */
1555 static void
1556 gem_rint(sc)
1557 	struct gem_softc *sc;
1558 {
1559 	struct ifnet *ifp = sc->sc_ifp;
1560 	struct gem_rxsoft *rxs;
1561 	struct mbuf *m;
1562 	u_int64_t rxstat;
1563 	u_int32_t rxcomp;
1564 	int i, len, progress = 0;
1565 
1566 #ifdef GEM_RINT_TIMEOUT
1567 	callout_stop(&sc->sc_rx_ch);
1568 #endif
1569 #ifdef GEM_DEBUG
1570 	CTR2(KTR_GEM, "%s: %s", device_get_name(sc->sc_dev), __func__);
1571 #endif
1572 
1573 	/*
1574 	 * Read the completion register once.  This limits
1575 	 * how long the following loop can execute.
1576 	 */
1577 	rxcomp = bus_read_4(sc->sc_res[0], GEM_RX_COMPLETION);
1578 
1579 #ifdef GEM_DEBUG
1580 	CTR3(KTR_GEM, "%s: sc->rxptr %d, complete %d",
1581 	    __func__, sc->sc_rxptr, rxcomp);
1582 #endif
1583 	GEM_CDSYNC(sc, BUS_DMASYNC_POSTREAD);
1584 	for (i = sc->sc_rxptr; i != rxcomp;
1585 	     i = GEM_NEXTRX(i)) {
1586 		rxs = &sc->sc_rxsoft[i];
1587 
1588 		rxstat = GEM_DMA_READ(sc, sc->sc_rxdescs[i].gd_flags);
1589 
1590 		if (rxstat & GEM_RD_OWN) {
1591 #ifdef GEM_RINT_TIMEOUT
1592 			/*
1593 			 * The descriptor is still marked as owned, although
1594 			 * it is supposed to have completed. This has been
1595 			 * observed on some machines. Just exiting here
1596 			 * might leave the packet sitting around until another
1597 			 * one arrives to trigger a new interrupt, which is
1598 			 * generally undesirable, so set up a timeout.
1599 			 */
1600 			callout_reset(&sc->sc_rx_ch, GEM_RXOWN_TICKS,
1601 			    gem_rint_timeout, sc);
1602 #endif
1603 			break;
1604 		}
1605 
1606 		progress++;
1607 		ifp->if_ipackets++;
1608 
1609 		if (rxstat & GEM_RD_BAD_CRC) {
1610 			ifp->if_ierrors++;
1611 			device_printf(sc->sc_dev, "receive error: CRC error\n");
1612 			GEM_INIT_RXDESC(sc, i);
1613 			continue;
1614 		}
1615 
1616 #ifdef GEM_DEBUG
1617 		if (ifp->if_flags & IFF_DEBUG) {
1618 			printf("    rxsoft %p descriptor %d: ", rxs, i);
1619 			printf("gd_flags: 0x%016llx\t", (long long)
1620 				GEM_DMA_READ(sc, sc->sc_rxdescs[i].gd_flags));
1621 			printf("gd_addr: 0x%016llx\n", (long long)
1622 				GEM_DMA_READ(sc, sc->sc_rxdescs[i].gd_addr));
1623 		}
1624 #endif
1625 
1626 		/*
1627 		 * No errors; receive the packet.
1628 		 */
1629 		len = GEM_RD_BUFLEN(rxstat);
1630 
1631 		/*
1632 		 * Allocate a new mbuf cluster.  If that fails, we are
1633 		 * out of memory, and must drop the packet and recycle
1634 		 * the buffer that's already attached to this descriptor.
1635 		 */
1636 		m = rxs->rxs_mbuf;
1637 		if (gem_add_rxbuf(sc, i) != 0) {
1638 			ifp->if_ierrors++;
1639 			GEM_INIT_RXDESC(sc, i);
1640 			continue;
1641 		}
1642 		m->m_data += 2; /* We're already off by two */
1643 
1644 		m->m_pkthdr.rcvif = ifp;
1645 		m->m_pkthdr.len = m->m_len = len;
1646 
1647 		if ((ifp->if_capenable & IFCAP_RXCSUM) != 0)
1648 			gem_rxcksum(m, rxstat);
1649 
1650 		/* Pass it on. */
1651 		GEM_UNLOCK(sc);
1652 		(*ifp->if_input)(ifp, m);
1653 		GEM_LOCK(sc);
1654 	}
1655 
1656 	if (progress) {
1657 		GEM_CDSYNC(sc, BUS_DMASYNC_PREWRITE);
1658 		/* Update the receive pointer. */
1659 		if (i == sc->sc_rxptr) {
1660 			device_printf(sc->sc_dev, "rint: ring wrap\n");
1661 		}
1662 		sc->sc_rxptr = i;
1663 		bus_write_4(sc->sc_res[0], GEM_RX_KICK, GEM_PREVRX(i));
1664 	}
1665 
1666 #ifdef GEM_DEBUG
1667 	CTR3(KTR_GEM, "%s: done sc->rxptr %d, complete %d", __func__,
1668 		sc->sc_rxptr, bus_read_4(sc->sc_res[0], GEM_RX_COMPLETION));
1669 #endif
1670 }
1671 
1672 
1673 /*
1674  * gem_add_rxbuf:
1675  *
1676  *	Add a receive buffer to the indicated descriptor.
1677  */
1678 static int
1679 gem_add_rxbuf(sc, idx)
1680 	struct gem_softc *sc;
1681 	int idx;
1682 {
1683 	struct gem_rxsoft *rxs = &sc->sc_rxsoft[idx];
1684 	struct mbuf *m;
1685 	bus_dma_segment_t segs[1];
1686 	int error, nsegs;
1687 
1688 	m = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
1689 	if (m == NULL)
1690 		return (ENOBUFS);
1691 	m->m_len = m->m_pkthdr.len = m->m_ext.ext_size;
1692 
1693 #ifdef GEM_DEBUG
1694 	/* bzero the packet to check dma */
1695 	memset(m->m_ext.ext_buf, 0, m->m_ext.ext_size);
1696 #endif
1697 
1698 	if (rxs->rxs_mbuf != NULL) {
1699 		bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap,
1700 		    BUS_DMASYNC_POSTREAD);
1701 		bus_dmamap_unload(sc->sc_rdmatag, rxs->rxs_dmamap);
1702 	}
1703 
1704 	rxs->rxs_mbuf = m;
1705 
1706 	error = bus_dmamap_load_mbuf_sg(sc->sc_rdmatag, rxs->rxs_dmamap,
1707 	    m, segs, &nsegs, BUS_DMA_NOWAIT);
1708 	/* If nsegs is wrong then the stack is corrupt. */
1709 	KASSERT(nsegs == 1, ("Too many segments returned!"));
1710 	if (error != 0) {
1711 		device_printf(sc->sc_dev, "can't load rx DMA map %d, error = "
1712 		    "%d\n", idx, error);
1713 		m_freem(m);
1714 		return (ENOBUFS);
1715 	}
1716 	rxs->rxs_paddr = segs[0].ds_addr;
1717 
1718 	bus_dmamap_sync(sc->sc_rdmatag, rxs->rxs_dmamap, BUS_DMASYNC_PREREAD);
1719 
1720 	GEM_INIT_RXDESC(sc, idx);
1721 
1722 	return (0);
1723 }
1724 
1725 
1726 static void
1727 gem_eint(sc, status)
1728 	struct gem_softc *sc;
1729 	u_int status;
1730 {
1731 
1732 	if ((status & GEM_INTR_MIF) != 0) {
1733 		device_printf(sc->sc_dev, "XXXlink status changed\n");
1734 		return;
1735 	}
1736 
1737 	device_printf(sc->sc_dev, "status=%x\n", status);
1738 }
1739 
1740 
1741 void
1742 gem_intr(v)
1743 	void *v;
1744 {
1745 	struct gem_softc *sc = (struct gem_softc *)v;
1746 	u_int32_t status;
1747 
1748 	GEM_LOCK(sc);
1749 	status = bus_read_4(sc->sc_res[0], GEM_STATUS);
1750 #ifdef GEM_DEBUG
1751 	CTR4(KTR_GEM, "%s: %s: cplt %x, status %x",
1752 		device_get_name(sc->sc_dev), __func__, (status>>19),
1753 		(u_int)status);
1754 #endif
1755 
1756 	if ((status & (GEM_INTR_RX_TAG_ERR | GEM_INTR_BERR)) != 0)
1757 		gem_eint(sc, status);
1758 
1759 	if ((status & (GEM_INTR_TX_EMPTY | GEM_INTR_TX_INTME)) != 0)
1760 		gem_tint(sc);
1761 
1762 	if ((status & (GEM_INTR_RX_DONE | GEM_INTR_RX_NOBUF)) != 0)
1763 		gem_rint(sc);
1764 
1765 	/* We should eventually do more than just print out error stats. */
1766 	if (status & GEM_INTR_TX_MAC) {
1767 		int txstat = bus_read_4(sc->sc_res[0], GEM_MAC_TX_STATUS);
1768 		if (txstat & ~GEM_MAC_TX_XMIT_DONE)
1769 			device_printf(sc->sc_dev, "MAC tx fault, status %x\n",
1770 			    txstat);
1771 		if (txstat & (GEM_MAC_TX_UNDERRUN | GEM_MAC_TX_PKT_TOO_LONG))
1772 			gem_init_locked(sc);
1773 	}
1774 	if (status & GEM_INTR_RX_MAC) {
1775 		int rxstat = bus_read_4(sc->sc_res[0], GEM_MAC_RX_STATUS);
1776 		/*
1777 		 * On some chip revisions GEM_MAC_RX_OVERFLOW happen often
1778 		 * due to a silicon bug so handle them silently.
1779 		 */
1780 		if (rxstat & GEM_MAC_RX_OVERFLOW)
1781 			gem_init_locked(sc);
1782 		else if (rxstat & ~(GEM_MAC_RX_DONE | GEM_MAC_RX_FRAME_CNT))
1783 			device_printf(sc->sc_dev, "MAC rx fault, status %x\n",
1784 			    rxstat);
1785 	}
1786 	GEM_UNLOCK(sc);
1787 }
1788 
1789 static int
1790 gem_watchdog(sc)
1791 	struct gem_softc *sc;
1792 {
1793 
1794 	GEM_LOCK_ASSERT(sc, MA_OWNED);
1795 
1796 #ifdef GEM_DEBUG
1797 	CTR4(KTR_GEM, "%s: GEM_RX_CONFIG %x GEM_MAC_RX_STATUS %x "
1798 		"GEM_MAC_RX_CONFIG %x", __func__,
1799 		bus_read_4(sc->sc_res[0], GEM_RX_CONFIG),
1800 		bus_read_4(sc->sc_res[0], GEM_MAC_RX_STATUS),
1801 		bus_read_4(sc->sc_res[0], GEM_MAC_RX_CONFIG));
1802 	CTR4(KTR_GEM, "%s: GEM_TX_CONFIG %x GEM_MAC_TX_STATUS %x "
1803 		"GEM_MAC_TX_CONFIG %x", __func__,
1804 		bus_read_4(sc->sc_res[0], GEM_TX_CONFIG),
1805 		bus_read_4(sc->sc_res[0], GEM_MAC_TX_STATUS),
1806 		bus_read_4(sc->sc_res[0], GEM_MAC_TX_CONFIG));
1807 #endif
1808 
1809 	if (sc->sc_wdog_timer == 0 || --sc->sc_wdog_timer != 0)
1810 		return (0);
1811 
1812 	device_printf(sc->sc_dev, "device timeout\n");
1813 	++sc->sc_ifp->if_oerrors;
1814 
1815 	/* Try to get more packets going. */
1816 	gem_init_locked(sc);
1817 	return (EJUSTRETURN);
1818 }
1819 
1820 /*
1821  * Initialize the MII Management Interface
1822  */
1823 static void
1824 gem_mifinit(sc)
1825 	struct gem_softc *sc;
1826 {
1827 
1828 	/* Configure the MIF in frame mode */
1829 	sc->sc_mif_config = bus_read_4(sc->sc_res[0], GEM_MIF_CONFIG);
1830 	sc->sc_mif_config &= ~GEM_MIF_CONFIG_BB_ENA;
1831 	bus_write_4(sc->sc_res[0], GEM_MIF_CONFIG, sc->sc_mif_config);
1832 }
1833 
1834 /*
1835  * MII interface
1836  *
1837  * The GEM MII interface supports at least three different operating modes:
1838  *
1839  * Bitbang mode is implemented using data, clock and output enable registers.
1840  *
1841  * Frame mode is implemented by loading a complete frame into the frame
1842  * register and polling the valid bit for completion.
1843  *
1844  * Polling mode uses the frame register but completion is indicated by
1845  * an interrupt.
1846  *
1847  */
1848 int
1849 gem_mii_readreg(dev, phy, reg)
1850 	device_t dev;
1851 	int phy, reg;
1852 {
1853 	struct gem_softc *sc = device_get_softc(dev);
1854 	int n;
1855 	u_int32_t v;
1856 
1857 #ifdef GEM_DEBUG_PHY
1858 	printf("gem_mii_readreg: phy %d reg %d\n", phy, reg);
1859 #endif
1860 
1861 #if 0
1862 	/* Select the desired PHY in the MIF configuration register */
1863 	v = bus_read_4(sc->sc_res[0], GEM_MIF_CONFIG);
1864 	/* Clear PHY select bit */
1865 	v &= ~GEM_MIF_CONFIG_PHY_SEL;
1866 	if (phy == GEM_PHYAD_EXTERNAL)
1867 		/* Set PHY select bit to get at external device */
1868 		v |= GEM_MIF_CONFIG_PHY_SEL;
1869 	bus_write_4(sc->sc_res[0], GEM_MIF_CONFIG, v);
1870 #endif
1871 
1872 	/* Construct the frame command */
1873 	v = (reg << GEM_MIF_REG_SHIFT)	| (phy << GEM_MIF_PHY_SHIFT) |
1874 		GEM_MIF_FRAME_READ;
1875 
1876 	bus_write_4(sc->sc_res[0], GEM_MIF_FRAME, v);
1877 	for (n = 0; n < 100; n++) {
1878 		DELAY(1);
1879 		v = bus_read_4(sc->sc_res[0], GEM_MIF_FRAME);
1880 		if (v & GEM_MIF_FRAME_TA0)
1881 			return (v & GEM_MIF_FRAME_DATA);
1882 	}
1883 
1884 	device_printf(sc->sc_dev, "mii_read timeout\n");
1885 	return (0);
1886 }
1887 
1888 int
1889 gem_mii_writereg(dev, phy, reg, val)
1890 	device_t dev;
1891 	int phy, reg, val;
1892 {
1893 	struct gem_softc *sc = device_get_softc(dev);
1894 	int n;
1895 	u_int32_t v;
1896 
1897 #ifdef GEM_DEBUG_PHY
1898 	printf("gem_mii_writereg: phy %d reg %d val %x\n", phy, reg, val);
1899 #endif
1900 
1901 #if 0
1902 	/* Select the desired PHY in the MIF configuration register */
1903 	v = bus_read_4(sc->sc_res[0], GEM_MIF_CONFIG);
1904 	/* Clear PHY select bit */
1905 	v &= ~GEM_MIF_CONFIG_PHY_SEL;
1906 	if (phy == GEM_PHYAD_EXTERNAL)
1907 		/* Set PHY select bit to get at external device */
1908 		v |= GEM_MIF_CONFIG_PHY_SEL;
1909 	bus_write_4(sc->sc_res[0], GEM_MIF_CONFIG, v);
1910 #endif
1911 	/* Construct the frame command */
1912 	v = GEM_MIF_FRAME_WRITE			|
1913 	    (phy << GEM_MIF_PHY_SHIFT)		|
1914 	    (reg << GEM_MIF_REG_SHIFT)		|
1915 	    (val & GEM_MIF_FRAME_DATA);
1916 
1917 	bus_write_4(sc->sc_res[0], GEM_MIF_FRAME, v);
1918 	for (n = 0; n < 100; n++) {
1919 		DELAY(1);
1920 		v = bus_read_4(sc->sc_res[0], GEM_MIF_FRAME);
1921 		if (v & GEM_MIF_FRAME_TA0)
1922 			return (1);
1923 	}
1924 
1925 	device_printf(sc->sc_dev, "mii_write timeout\n");
1926 	return (0);
1927 }
1928 
1929 void
1930 gem_mii_statchg(dev)
1931 	device_t dev;
1932 {
1933 	struct gem_softc *sc = device_get_softc(dev);
1934 #ifdef GEM_DEBUG
1935 	int instance;
1936 #endif
1937 	u_int32_t v;
1938 
1939 #ifdef GEM_DEBUG
1940 	instance = IFM_INST(sc->sc_mii->mii_media.ifm_cur->ifm_media);
1941 	if (sc->sc_debug)
1942 		printf("gem_mii_statchg: status change: phy = %d\n",
1943 			sc->sc_phys[instance]);
1944 #endif
1945 
1946 	/* Set tx full duplex options */
1947 	bus_write_4(sc->sc_res[0], GEM_MAC_TX_CONFIG, 0);
1948 	DELAY(10000); /* reg must be cleared and delay before changing. */
1949 	v = GEM_MAC_TX_ENA_IPG0|GEM_MAC_TX_NGU|GEM_MAC_TX_NGU_LIMIT|
1950 		GEM_MAC_TX_ENABLE;
1951 	if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) != 0) {
1952 		v |= GEM_MAC_TX_IGN_CARRIER|GEM_MAC_TX_IGN_COLLIS;
1953 	}
1954 	bus_write_4(sc->sc_res[0], GEM_MAC_TX_CONFIG, v);
1955 
1956 	/* XIF Configuration */
1957 	v = GEM_MAC_XIF_LINK_LED;
1958 	v |= GEM_MAC_XIF_TX_MII_ENA;
1959 
1960 	/* If an external transceiver is connected, enable its MII drivers */
1961 	sc->sc_mif_config = bus_read_4(sc->sc_res[0], GEM_MIF_CONFIG);
1962 	if ((sc->sc_mif_config & GEM_MIF_CONFIG_MDI1) != 0) {
1963 		/* External MII needs echo disable if half duplex. */
1964 		if ((IFM_OPTIONS(sc->sc_mii->mii_media_active) & IFM_FDX) != 0)
1965 			/* turn on full duplex LED */
1966 			v |= GEM_MAC_XIF_FDPLX_LED;
1967 		else
1968 	 		/* half duplex -- disable echo */
1969 	 		v |= GEM_MAC_XIF_ECHO_DISABL;
1970 
1971 		if (IFM_SUBTYPE(sc->sc_mii->mii_media_active) == IFM_1000_T)
1972 			v |= GEM_MAC_XIF_GMII_MODE;
1973 		else
1974 			v &= ~GEM_MAC_XIF_GMII_MODE;
1975 	} else {
1976 		/* Internal MII needs buf enable */
1977 		v |= GEM_MAC_XIF_MII_BUF_ENA;
1978 	}
1979 	bus_write_4(sc->sc_res[0], GEM_MAC_XIF_CONFIG, v);
1980 }
1981 
1982 int
1983 gem_mediachange(ifp)
1984 	struct ifnet *ifp;
1985 {
1986 	struct gem_softc *sc = ifp->if_softc;
1987 	int error;
1988 
1989 	/* XXX Add support for serial media. */
1990 
1991 	GEM_LOCK(sc);
1992 	error = mii_mediachg(sc->sc_mii);
1993 	GEM_UNLOCK(sc);
1994 	return (error);
1995 }
1996 
1997 void
1998 gem_mediastatus(ifp, ifmr)
1999 	struct ifnet *ifp;
2000 	struct ifmediareq *ifmr;
2001 {
2002 	struct gem_softc *sc = ifp->if_softc;
2003 
2004 	GEM_LOCK(sc);
2005 	if ((ifp->if_flags & IFF_UP) == 0) {
2006 		GEM_UNLOCK(sc);
2007 		return;
2008 	}
2009 
2010 	mii_pollstat(sc->sc_mii);
2011 	ifmr->ifm_active = sc->sc_mii->mii_media_active;
2012 	ifmr->ifm_status = sc->sc_mii->mii_media_status;
2013 	GEM_UNLOCK(sc);
2014 }
2015 
2016 /*
2017  * Process an ioctl request.
2018  */
2019 static int
2020 gem_ioctl(ifp, cmd, data)
2021 	struct ifnet *ifp;
2022 	u_long cmd;
2023 	caddr_t data;
2024 {
2025 	struct gem_softc *sc = ifp->if_softc;
2026 	struct ifreq *ifr = (struct ifreq *)data;
2027 	int error = 0;
2028 
2029 	switch (cmd) {
2030 	case SIOCSIFFLAGS:
2031 		GEM_LOCK(sc);
2032 		if (ifp->if_flags & IFF_UP) {
2033 			if ((sc->sc_ifflags ^ ifp->if_flags) == IFF_PROMISC)
2034 				gem_setladrf(sc);
2035 			else
2036 				gem_init_locked(sc);
2037 		} else {
2038 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
2039 				gem_stop(ifp, 0);
2040 		}
2041 		if ((ifp->if_flags & IFF_LINK0) != 0)
2042 			sc->sc_csum_features |= CSUM_UDP;
2043 		else
2044 			sc->sc_csum_features &= ~CSUM_UDP;
2045 		if ((ifp->if_capenable & IFCAP_TXCSUM) != 0)
2046 			ifp->if_hwassist = sc->sc_csum_features;
2047 		sc->sc_ifflags = ifp->if_flags;
2048 		GEM_UNLOCK(sc);
2049 		break;
2050 	case SIOCADDMULTI:
2051 	case SIOCDELMULTI:
2052 		GEM_LOCK(sc);
2053 		gem_setladrf(sc);
2054 		GEM_UNLOCK(sc);
2055 		break;
2056 	case SIOCGIFMEDIA:
2057 	case SIOCSIFMEDIA:
2058 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_mii->mii_media, cmd);
2059 		break;
2060 	case SIOCSIFCAP:
2061 		GEM_LOCK(sc);
2062 		ifp->if_capenable = ifr->ifr_reqcap;
2063 		if ((ifp->if_capenable & IFCAP_TXCSUM) != 0)
2064 			ifp->if_hwassist = sc->sc_csum_features;
2065 		else
2066 			ifp->if_hwassist = 0;
2067 		GEM_UNLOCK(sc);
2068 		break;
2069 	default:
2070 		error = ether_ioctl(ifp, cmd, data);
2071 		break;
2072 	}
2073 
2074 	return (error);
2075 }
2076 
2077 /*
2078  * Set up the logical address filter.
2079  */
2080 static void
2081 gem_setladrf(sc)
2082 	struct gem_softc *sc;
2083 {
2084 	struct ifnet *ifp = sc->sc_ifp;
2085 	struct ifmultiaddr *inm;
2086 	u_int32_t crc;
2087 	u_int32_t hash[16];
2088 	u_int32_t v;
2089 	int i;
2090 
2091 	GEM_LOCK_ASSERT(sc, MA_OWNED);
2092 
2093 	/* Get current RX configuration */
2094 	v = bus_read_4(sc->sc_res[0], GEM_MAC_RX_CONFIG);
2095 
2096 	/*
2097 	 * Turn off promiscuous mode, promiscuous group mode (all multicast),
2098 	 * and hash filter.  Depending on the case, the right bit will be
2099 	 * enabled.
2100 	 */
2101 	v &= ~(GEM_MAC_RX_PROMISCUOUS|GEM_MAC_RX_HASH_FILTER|
2102 	    GEM_MAC_RX_PROMISC_GRP);
2103 
2104 	if ((ifp->if_flags & IFF_PROMISC) != 0) {
2105 		/* Turn on promiscuous mode */
2106 		v |= GEM_MAC_RX_PROMISCUOUS;
2107 		goto chipit;
2108 	}
2109 	if ((ifp->if_flags & IFF_ALLMULTI) != 0) {
2110 		hash[3] = hash[2] = hash[1] = hash[0] = 0xffff;
2111 		ifp->if_flags |= IFF_ALLMULTI;
2112 		v |= GEM_MAC_RX_PROMISC_GRP;
2113 		goto chipit;
2114 	}
2115 
2116 	/*
2117 	 * Set up multicast address filter by passing all multicast addresses
2118 	 * through a crc generator, and then using the high order 8 bits as an
2119 	 * index into the 256 bit logical address filter.  The high order 4
2120 	 * bits selects the word, while the other 4 bits select the bit within
2121 	 * the word (where bit 0 is the MSB).
2122 	 */
2123 
2124 	/* Clear hash table */
2125 	memset(hash, 0, sizeof(hash));
2126 
2127 	IF_ADDR_LOCK(ifp);
2128 	TAILQ_FOREACH(inm, &ifp->if_multiaddrs, ifma_link) {
2129 		if (inm->ifma_addr->sa_family != AF_LINK)
2130 			continue;
2131 		crc = ether_crc32_le(LLADDR((struct sockaddr_dl *)
2132 		    inm->ifma_addr), ETHER_ADDR_LEN);
2133 
2134 		/* Just want the 8 most significant bits. */
2135 		crc >>= 24;
2136 
2137 		/* Set the corresponding bit in the filter. */
2138 		hash[crc >> 4] |= 1 << (15 - (crc & 15));
2139 	}
2140 	IF_ADDR_UNLOCK(ifp);
2141 
2142 	v |= GEM_MAC_RX_HASH_FILTER;
2143 	ifp->if_flags &= ~IFF_ALLMULTI;
2144 
2145 	/* Now load the hash table into the chip (if we are using it) */
2146 	for (i = 0; i < 16; i++) {
2147 		bus_write_4(sc->sc_res[0],
2148 		    GEM_MAC_HASH0 + i * (GEM_MAC_HASH1-GEM_MAC_HASH0),
2149 		    hash[i]);
2150 	}
2151 
2152 chipit:
2153 	bus_write_4(sc->sc_res[0], GEM_MAC_RX_CONFIG, v);
2154 }
2155