xref: /netbsd-src/sys/dev/pci/if_pcn.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: if_pcn.c,v 1.65 2018/06/26 06:48:01 msaitoh Exp $	*/
2 
3 /*
4  * Copyright (c) 2001 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
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  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed for the NetBSD Project by
20  *	Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 /*
39  * Device driver for the AMD PCnet-PCI series of Ethernet
40  * chips:
41  *
42  *	* Am79c970 PCnet-PCI Single-Chip Ethernet Controller for PCI
43  *	  Local Bus
44  *
45  *	* Am79c970A PCnet-PCI II Single-Chip Full-Duplex Ethernet Controller
46  *	  for PCI Local Bus
47  *
48  *	* Am79c971 PCnet-FAST Single-Chip Full-Duplex 10/100Mbps
49  *	  Ethernet Controller for PCI Local Bus
50  *
51  *	* Am79c972 PCnet-FAST+ Enhanced 10/100Mbps PCI Ethernet Controller
52  *	  with OnNow Support
53  *
54  *	* Am79c973/Am79c975 PCnet-FAST III Single-Chip 10/100Mbps PCI
55  *	  Ethernet Controller with Integrated PHY
56  *
57  * This also supports the virtual PCnet-PCI Ethernet interface found
58  * in VMware.
59  *
60  * TODO:
61  *
62  *	* Split this into bus-specific and bus-independent portions.
63  *	  The core could also be used for the ILACC (Am79900) 32-bit
64  *	  Ethernet chip (XXX only if we use an ILACC-compatible SWSTYLE).
65  */
66 
67 #include <sys/cdefs.h>
68 __KERNEL_RCSID(0, "$NetBSD: if_pcn.c,v 1.65 2018/06/26 06:48:01 msaitoh Exp $");
69 
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/callout.h>
73 #include <sys/mbuf.h>
74 #include <sys/malloc.h>
75 #include <sys/kernel.h>
76 #include <sys/socket.h>
77 #include <sys/ioctl.h>
78 #include <sys/errno.h>
79 #include <sys/device.h>
80 #include <sys/queue.h>
81 
82 #include <sys/rndsource.h>
83 
84 #include <net/if.h>
85 #include <net/if_dl.h>
86 #include <net/if_media.h>
87 #include <net/if_ether.h>
88 
89 #include <net/bpf.h>
90 
91 #include <sys/bus.h>
92 #include <sys/intr.h>
93 #include <machine/endian.h>
94 
95 #include <dev/mii/mii.h>
96 #include <dev/mii/miivar.h>
97 
98 #include <dev/ic/am79900reg.h>
99 #include <dev/ic/lancereg.h>
100 
101 #include <dev/pci/pcireg.h>
102 #include <dev/pci/pcivar.h>
103 #include <dev/pci/pcidevs.h>
104 
105 #include <dev/pci/if_pcnreg.h>
106 
107 /*
108  * Transmit descriptor list size.  This is arbitrary, but allocate
109  * enough descriptors for 128 pending transmissions, and 4 segments
110  * per packet.  This MUST work out to a power of 2.
111  *
112  * NOTE: We can't have any more than 512 Tx descriptors, SO BE CAREFUL!
113  *
114  * So we play a little trick here.  We give each packet up to 16
115  * DMA segments, but only allocate the max of 512 descriptors.  The
116  * transmit logic can deal with this, we just are hoping to sneak by.
117  */
118 #define	PCN_NTXSEGS		16
119 #define	PCN_NTXSEGS_VMWARE	8	/* bug in VMware's emulation */
120 
121 #define	PCN_TXQUEUELEN		128
122 #define	PCN_TXQUEUELEN_MASK	(PCN_TXQUEUELEN - 1)
123 #define	PCN_NTXDESC		512
124 #define	PCN_NTXDESC_MASK	(PCN_NTXDESC - 1)
125 #define	PCN_NEXTTX(x)		(((x) + 1) & PCN_NTXDESC_MASK)
126 #define	PCN_NEXTTXS(x)		(((x) + 1) & PCN_TXQUEUELEN_MASK)
127 
128 /* Tx interrupt every N + 1 packets. */
129 #define	PCN_TXINTR_MASK		7
130 
131 /*
132  * Receive descriptor list size.  We have one Rx buffer per incoming
133  * packet, so this logic is a little simpler.
134  */
135 #define	PCN_NRXDESC		128
136 #define	PCN_NRXDESC_MASK	(PCN_NRXDESC - 1)
137 #define	PCN_NEXTRX(x)		(((x) + 1) & PCN_NRXDESC_MASK)
138 
139 /*
140  * Control structures are DMA'd to the PCnet chip.  We allocate them in
141  * a single clump that maps to a single DMA segment to make several things
142  * easier.
143  */
144 struct pcn_control_data {
145 	/* The transmit descriptors. */
146 	struct letmd pcd_txdescs[PCN_NTXDESC];
147 
148 	/* The receive descriptors. */
149 	struct lermd pcd_rxdescs[PCN_NRXDESC];
150 
151 	/* The init block. */
152 	struct leinit pcd_initblock;
153 };
154 
155 #define	PCN_CDOFF(x)	offsetof(struct pcn_control_data, x)
156 #define	PCN_CDTXOFF(x)	PCN_CDOFF(pcd_txdescs[(x)])
157 #define	PCN_CDRXOFF(x)	PCN_CDOFF(pcd_rxdescs[(x)])
158 #define	PCN_CDINITOFF	PCN_CDOFF(pcd_initblock)
159 
160 /*
161  * Software state for transmit jobs.
162  */
163 struct pcn_txsoft {
164 	struct mbuf *txs_mbuf;		/* head of our mbuf chain */
165 	bus_dmamap_t txs_dmamap;	/* our DMA map */
166 	int txs_firstdesc;		/* first descriptor in packet */
167 	int txs_lastdesc;		/* last descriptor in packet */
168 };
169 
170 /*
171  * Software state for receive jobs.
172  */
173 struct pcn_rxsoft {
174 	struct mbuf *rxs_mbuf;		/* head of our mbuf chain */
175 	bus_dmamap_t rxs_dmamap;	/* our DMA map */
176 };
177 
178 /*
179  * Description of Rx FIFO watermarks for various revisions.
180  */
181 static const char * const pcn_79c970_rcvfw[] = {
182 	"16 bytes",
183 	"64 bytes",
184 	"128 bytes",
185 	NULL,
186 };
187 
188 static const char * const pcn_79c971_rcvfw[] = {
189 	"16 bytes",
190 	"64 bytes",
191 	"112 bytes",
192 	NULL,
193 };
194 
195 /*
196  * Description of Tx start points for various revisions.
197  */
198 static const char * const pcn_79c970_xmtsp[] = {
199 	"8 bytes",
200 	"64 bytes",
201 	"128 bytes",
202 	"248 bytes",
203 };
204 
205 static const char * const pcn_79c971_xmtsp[] = {
206 	"20 bytes",
207 	"64 bytes",
208 	"128 bytes",
209 	"248 bytes",
210 };
211 
212 static const char * const pcn_79c971_xmtsp_sram[] = {
213 	"44 bytes",
214 	"64 bytes",
215 	"128 bytes",
216 	"store-and-forward",
217 };
218 
219 /*
220  * Description of Tx FIFO watermarks for various revisions.
221  */
222 static const char * const pcn_79c970_xmtfw[] = {
223 	"16 bytes",
224 	"64 bytes",
225 	"128 bytes",
226 	NULL,
227 };
228 
229 static const char * const pcn_79c971_xmtfw[] = {
230 	"16 bytes",
231 	"64 bytes",
232 	"108 bytes",
233 	NULL,
234 };
235 
236 /*
237  * Software state per device.
238  */
239 struct pcn_softc {
240 	device_t sc_dev;		/* generic device information */
241 	bus_space_tag_t sc_st;		/* bus space tag */
242 	bus_space_handle_t sc_sh;	/* bus space handle */
243 	bus_dma_tag_t sc_dmat;		/* bus DMA tag */
244 	struct ethercom sc_ethercom;	/* Ethernet common data */
245 
246 	/* Points to our media routines, etc. */
247 	const struct pcn_variant *sc_variant;
248 
249 	void *sc_ih;			/* interrupt cookie */
250 
251 	struct mii_data sc_mii;		/* MII/media information */
252 
253 	callout_t sc_tick_ch;		/* tick callout */
254 
255 	bus_dmamap_t sc_cddmamap;	/* control data DMA map */
256 #define	sc_cddma	sc_cddmamap->dm_segs[0].ds_addr
257 
258 	/* Software state for transmit and receive descriptors. */
259 	struct pcn_txsoft sc_txsoft[PCN_TXQUEUELEN];
260 	struct pcn_rxsoft sc_rxsoft[PCN_NRXDESC];
261 
262 	/* Control data structures */
263 	struct pcn_control_data *sc_control_data;
264 #define	sc_txdescs	sc_control_data->pcd_txdescs
265 #define	sc_rxdescs	sc_control_data->pcd_rxdescs
266 #define	sc_initblock	sc_control_data->pcd_initblock
267 
268 #ifdef PCN_EVENT_COUNTERS
269 	/* Event counters. */
270 	struct evcnt sc_ev_txsstall;	/* Tx stalled due to no txs */
271 	struct evcnt sc_ev_txdstall;	/* Tx stalled due to no txd */
272 	struct evcnt sc_ev_txintr;	/* Tx interrupts */
273 	struct evcnt sc_ev_rxintr;	/* Rx interrupts */
274 	struct evcnt sc_ev_babl;	/* BABL in pcn_intr() */
275 	struct evcnt sc_ev_miss;	/* MISS in pcn_intr() */
276 	struct evcnt sc_ev_merr;	/* MERR in pcn_intr() */
277 
278 	struct evcnt sc_ev_txseg1;	/* Tx packets w/ 1 segment */
279 	struct evcnt sc_ev_txseg2;	/* Tx packets w/ 2 segments */
280 	struct evcnt sc_ev_txseg3;	/* Tx packets w/ 3 segments */
281 	struct evcnt sc_ev_txseg4;	/* Tx packets w/ 4 segments */
282 	struct evcnt sc_ev_txseg5;	/* Tx packets w/ 5 segments */
283 	struct evcnt sc_ev_txsegmore;	/* Tx packets w/ more than 5 segments */
284 	struct evcnt sc_ev_txcopy;	/* Tx copies required */
285 #endif /* PCN_EVENT_COUNTERS */
286 
287 	const char * const *sc_rcvfw_desc;	/* Rx FIFO watermark info */
288 	int sc_rcvfw;
289 
290 	const char * const *sc_xmtsp_desc;	/* Tx start point info */
291 	int sc_xmtsp;
292 
293 	const char * const *sc_xmtfw_desc;	/* Tx FIFO watermark info */
294 	int sc_xmtfw;
295 
296 	int sc_flags;			/* misc. flags; see below */
297 	int sc_swstyle;			/* the software style in use */
298 
299 	int sc_txfree;			/* number of free Tx descriptors */
300 	int sc_txnext;			/* next ready Tx descriptor */
301 
302 	int sc_txsfree;			/* number of free Tx jobs */
303 	int sc_txsnext;			/* next free Tx job */
304 	int sc_txsdirty;		/* dirty Tx jobs */
305 
306 	int sc_rxptr;			/* next ready Rx descriptor/job */
307 
308 	uint32_t sc_csr5;		/* prototype CSR5 register */
309 	uint32_t sc_mode;		/* prototype MODE register */
310 
311 	krndsource_t rnd_source;	/* random source */
312 };
313 
314 /* sc_flags */
315 #define	PCN_F_HAS_MII		0x0001	/* has MII */
316 
317 #ifdef PCN_EVENT_COUNTERS
318 #define	PCN_EVCNT_INCR(ev)	(ev)->ev_count++
319 #else
320 #define	PCN_EVCNT_INCR(ev)	/* nothing */
321 #endif
322 
323 #define	PCN_CDTXADDR(sc, x)	((sc)->sc_cddma + PCN_CDTXOFF((x)))
324 #define	PCN_CDRXADDR(sc, x)	((sc)->sc_cddma + PCN_CDRXOFF((x)))
325 #define	PCN_CDINITADDR(sc)	((sc)->sc_cddma + PCN_CDINITOFF)
326 
327 #define	PCN_CDTXSYNC(sc, x, n, ops)					\
328 do {									\
329 	int __x, __n;							\
330 									\
331 	__x = (x);							\
332 	__n = (n);							\
333 									\
334 	/* If it will wrap around, sync to the end of the ring. */	\
335 	if ((__x + __n) > PCN_NTXDESC) {				\
336 		bus_dmamap_sync((sc)->sc_dmat, (sc)->sc_cddmamap,	\
337 		    PCN_CDTXOFF(__x), sizeof(struct letmd) *		\
338 		    (PCN_NTXDESC - __x), (ops));			\
339 		__n -= (PCN_NTXDESC - __x);				\
340 		__x = 0;						\
341 	}								\
342 									\
343 	/* Now sync whatever is left. */				\
344 	bus_dmamap_sync((sc)->sc_dmat, (sc)->sc_cddmamap,		\
345 	    PCN_CDTXOFF(__x), sizeof(struct letmd) * __n, (ops));	\
346 } while (/*CONSTCOND*/0)
347 
348 #define	PCN_CDRXSYNC(sc, x, ops)					\
349 	bus_dmamap_sync((sc)->sc_dmat, (sc)->sc_cddmamap,		\
350 	    PCN_CDRXOFF((x)), sizeof(struct lermd), (ops))
351 
352 #define	PCN_CDINITSYNC(sc, ops)						\
353 	bus_dmamap_sync((sc)->sc_dmat, (sc)->sc_cddmamap,		\
354 	    PCN_CDINITOFF, sizeof(struct leinit), (ops))
355 
356 #define	PCN_INIT_RXDESC(sc, x)						\
357 do {									\
358 	struct pcn_rxsoft *__rxs = &(sc)->sc_rxsoft[(x)];		\
359 	struct lermd *__rmd = &(sc)->sc_rxdescs[(x)];			\
360 	struct mbuf *__m = __rxs->rxs_mbuf;				\
361 									\
362 	/*								\
363 	 * Note: We scoot the packet forward 2 bytes in the buffer	\
364 	 * so that the payload after the Ethernet header is aligned	\
365 	 * to a 4-byte boundary.					\
366 	 */								\
367 	__m->m_data = __m->m_ext.ext_buf + 2;				\
368 									\
369 	if ((sc)->sc_swstyle == LE_B20_SSTYLE_PCNETPCI3) {		\
370 		__rmd->rmd2 =						\
371 		    htole32(__rxs->rxs_dmamap->dm_segs[0].ds_addr + 2);	\
372 		__rmd->rmd0 = 0;					\
373 	} else {							\
374 		__rmd->rmd2 = 0;					\
375 		__rmd->rmd0 =						\
376 		    htole32(__rxs->rxs_dmamap->dm_segs[0].ds_addr + 2);	\
377 	}								\
378 	__rmd->rmd1 = htole32(LE_R1_OWN|LE_R1_ONES| 			\
379 	    (LE_BCNT(MCLBYTES - 2) & LE_R1_BCNT_MASK));			\
380 	PCN_CDRXSYNC((sc), (x), BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);\
381 } while(/*CONSTCOND*/0)
382 
383 static void	pcn_start(struct ifnet *);
384 static void	pcn_watchdog(struct ifnet *);
385 static int	pcn_ioctl(struct ifnet *, u_long, void *);
386 static int	pcn_init(struct ifnet *);
387 static void	pcn_stop(struct ifnet *, int);
388 
389 static bool	pcn_shutdown(device_t, int);
390 
391 static void	pcn_reset(struct pcn_softc *);
392 static void	pcn_rxdrain(struct pcn_softc *);
393 static int	pcn_add_rxbuf(struct pcn_softc *, int);
394 static void	pcn_tick(void *);
395 
396 static void	pcn_spnd(struct pcn_softc *);
397 
398 static void	pcn_set_filter(struct pcn_softc *);
399 
400 static int	pcn_intr(void *);
401 static void	pcn_txintr(struct pcn_softc *);
402 static int	pcn_rxintr(struct pcn_softc *);
403 
404 static int	pcn_mii_readreg(device_t, int, int);
405 static void	pcn_mii_writereg(device_t, int, int, int);
406 static void	pcn_mii_statchg(struct ifnet *);
407 
408 static void	pcn_79c970_mediainit(struct pcn_softc *);
409 static int	pcn_79c970_mediachange(struct ifnet *);
410 static void	pcn_79c970_mediastatus(struct ifnet *, struct ifmediareq *);
411 
412 static void	pcn_79c971_mediainit(struct pcn_softc *);
413 
414 /*
415  * Description of a PCnet-PCI variant.  Used to select media access
416  * method, mostly, and to print a nice description of the chip.
417  */
418 static const struct pcn_variant {
419 	const char *pcv_desc;
420 	void (*pcv_mediainit)(struct pcn_softc *);
421 	uint16_t pcv_chipid;
422 } pcn_variants[] = {
423 	{ "Am79c970 PCnet-PCI",
424 	  pcn_79c970_mediainit,
425 	  PARTID_Am79c970 },
426 
427 	{ "Am79c970A PCnet-PCI II",
428 	  pcn_79c970_mediainit,
429 	  PARTID_Am79c970A },
430 
431 	{ "Am79c971 PCnet-FAST",
432 	  pcn_79c971_mediainit,
433 	  PARTID_Am79c971 },
434 
435 	{ "Am79c972 PCnet-FAST+",
436 	  pcn_79c971_mediainit,
437 	  PARTID_Am79c972 },
438 
439 	{ "Am79c973 PCnet-FAST III",
440 	  pcn_79c971_mediainit,
441 	  PARTID_Am79c973 },
442 
443 	{ "Am79c975 PCnet-FAST III",
444 	  pcn_79c971_mediainit,
445 	  PARTID_Am79c975 },
446 
447 	{ "Unknown PCnet-PCI variant",
448 	  pcn_79c971_mediainit,
449 	  0 },
450 };
451 
452 int	pcn_copy_small = 0;
453 
454 static int	pcn_match(device_t, cfdata_t, void *);
455 static void	pcn_attach(device_t, device_t, void *);
456 
457 CFATTACH_DECL_NEW(pcn, sizeof(struct pcn_softc),
458     pcn_match, pcn_attach, NULL, NULL);
459 
460 /*
461  * Routines to read and write the PCnet-PCI CSR/BCR space.
462  */
463 
464 static inline uint32_t
465 pcn_csr_read(struct pcn_softc *sc, int reg)
466 {
467 
468 	bus_space_write_4(sc->sc_st, sc->sc_sh, PCN32_RAP, reg);
469 	return (bus_space_read_4(sc->sc_st, sc->sc_sh, PCN32_RDP));
470 }
471 
472 static inline void
473 pcn_csr_write(struct pcn_softc *sc, int reg, uint32_t val)
474 {
475 
476 	bus_space_write_4(sc->sc_st, sc->sc_sh, PCN32_RAP, reg);
477 	bus_space_write_4(sc->sc_st, sc->sc_sh, PCN32_RDP, val);
478 }
479 
480 static inline uint32_t
481 pcn_bcr_read(struct pcn_softc *sc, int reg)
482 {
483 
484 	bus_space_write_4(sc->sc_st, sc->sc_sh, PCN32_RAP, reg);
485 	return (bus_space_read_4(sc->sc_st, sc->sc_sh, PCN32_BDP));
486 }
487 
488 static inline void
489 pcn_bcr_write(struct pcn_softc *sc, int reg, uint32_t val)
490 {
491 
492 	bus_space_write_4(sc->sc_st, sc->sc_sh, PCN32_RAP, reg);
493 	bus_space_write_4(sc->sc_st, sc->sc_sh, PCN32_BDP, val);
494 }
495 
496 static bool
497 pcn_is_vmware(const char *enaddr)
498 {
499 
500 	/*
501 	 * VMware uses the OUI 00:0c:29 for auto-generated MAC
502 	 * addresses.
503 	 */
504 	if (enaddr[0] == 0x00 && enaddr[1] == 0x0c && enaddr[2] == 0x29)
505 		return (TRUE);
506 
507 	/*
508 	 * VMware uses the OUI 00:50:56 for manually-set MAC
509 	 * addresses (and some auto-generated ones).
510 	 */
511 	if (enaddr[0] == 0x00 && enaddr[1] == 0x50 && enaddr[2] == 0x56)
512 		return (TRUE);
513 
514 	return (FALSE);
515 }
516 
517 static const struct pcn_variant *
518 pcn_lookup_variant(uint16_t chipid)
519 {
520 	const struct pcn_variant *pcv;
521 
522 	for (pcv = pcn_variants; pcv->pcv_chipid != 0; pcv++) {
523 		if (chipid == pcv->pcv_chipid)
524 			return (pcv);
525 	}
526 
527 	/*
528 	 * This covers unknown chips, which we simply treat like
529 	 * a generic PCnet-FAST.
530 	 */
531 	return (pcv);
532 }
533 
534 static int
535 pcn_match(device_t parent, cfdata_t cf, void *aux)
536 {
537 	struct pci_attach_args *pa = aux;
538 
539 	/*
540 	 * IBM Makes a PCI variant of this card which shows up as a
541 	 * Trident Microsystems 4DWAVE DX (ethernet network, revision 0x25)
542 	 * this card is truly a pcn card, so we have a special case match for
543 	 * it
544 	 */
545 
546 	if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_TRIDENT &&
547 	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_TRIDENT_4DWAVE_DX &&
548 	    PCI_CLASS(pa->pa_class) == PCI_CLASS_NETWORK)
549 		return(1);
550 
551 	if (PCI_VENDOR(pa->pa_id) != PCI_VENDOR_AMD)
552 		return (0);
553 
554 	switch (PCI_PRODUCT(pa->pa_id)) {
555 	case PCI_PRODUCT_AMD_PCNET_PCI:
556 		/* Beat if_le_pci.c */
557 		return (10);
558 	}
559 
560 	return (0);
561 }
562 
563 static void
564 pcn_attach(device_t parent, device_t self, void *aux)
565 {
566 	struct pcn_softc *sc = device_private(self);
567 	struct pci_attach_args *pa = aux;
568 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
569 	pci_chipset_tag_t pc = pa->pa_pc;
570 	pci_intr_handle_t ih;
571 	const char *intrstr = NULL;
572 	bus_space_tag_t iot, memt;
573 	bus_space_handle_t ioh, memh;
574 	bus_dma_segment_t seg;
575 	int ioh_valid, memh_valid;
576 	int ntxsegs, i, rseg, error;
577 	uint32_t chipid, reg;
578 	uint8_t enaddr[ETHER_ADDR_LEN];
579 	prop_object_t obj;
580 	bool is_vmware;
581 	char intrbuf[PCI_INTRSTR_LEN];
582 
583 	sc->sc_dev = self;
584 	callout_init(&sc->sc_tick_ch, 0);
585 
586 	aprint_normal(": AMD PCnet-PCI Ethernet\n");
587 
588 	/*
589 	 * Map the device.
590 	 */
591 	ioh_valid = (pci_mapreg_map(pa, PCN_PCI_CBIO, PCI_MAPREG_TYPE_IO, 0,
592 	    &iot, &ioh, NULL, NULL) == 0);
593 	memh_valid = (pci_mapreg_map(pa, PCN_PCI_CBMEM,
594 	    PCI_MAPREG_TYPE_MEM|PCI_MAPREG_MEM_TYPE_32BIT, 0,
595 	    &memt, &memh, NULL, NULL) == 0);
596 
597 	if (memh_valid) {
598 		sc->sc_st = memt;
599 		sc->sc_sh = memh;
600 	} else if (ioh_valid) {
601 		sc->sc_st = iot;
602 		sc->sc_sh = ioh;
603 	} else {
604 		aprint_error_dev(self, "unable to map device registers\n");
605 		return;
606 	}
607 
608 	sc->sc_dmat = pa->pa_dmat;
609 
610 	/* Make sure bus mastering is enabled. */
611 	pci_conf_write(pc, pa->pa_tag, PCI_COMMAND_STATUS_REG,
612 	    pci_conf_read(pc, pa->pa_tag, PCI_COMMAND_STATUS_REG) |
613 	    PCI_COMMAND_MASTER_ENABLE);
614 
615 	/* power up chip */
616 	if ((error = pci_activate(pa->pa_pc, pa->pa_tag, self,
617 	    NULL)) && error != EOPNOTSUPP) {
618 		aprint_error_dev(self, "cannot activate %d\n", error);
619 		return;
620 	}
621 
622 	/*
623 	 * Reset the chip to a known state.  This also puts the
624 	 * chip into 32-bit mode.
625 	 */
626 	pcn_reset(sc);
627 
628 	/*
629 	 * On some systems with the chip is an on-board device, the
630 	 * EEPROM is not used.  Handle this by reading the MAC address
631 	 * from the CSRs (assuming that boot firmware has written
632 	 * it there).
633 	 */
634 	obj = prop_dictionary_get(device_properties(sc->sc_dev),
635 				  "am79c970-no-eeprom");
636 	if (prop_bool_true(obj)) {
637 	        for (i = 0; i < 3; i++) {
638 			uint32_t val;
639 			val = pcn_csr_read(sc, LE_CSR12 + i);
640 			enaddr[2 * i] = val & 0xff;
641 			enaddr[2 * i + 1] = (val >> 8) & 0xff;
642 		}
643 	} else {
644 		for (i = 0; i < ETHER_ADDR_LEN; i++) {
645 			enaddr[i] = bus_space_read_1(sc->sc_st, sc->sc_sh,
646 			    PCN32_APROM + i);
647 		}
648 	}
649 
650 	/* Check to see if this is a VMware emulated network interface. */
651 	is_vmware = pcn_is_vmware(enaddr);
652 
653 	/*
654 	 * Now that the device is mapped, attempt to figure out what
655 	 * kind of chip we have.  Note that IDL has all 32 bits of
656 	 * the chip ID when we're in 32-bit mode.
657 	 */
658 	chipid = pcn_csr_read(sc, LE_CSR88);
659 	sc->sc_variant = pcn_lookup_variant(CHIPID_PARTID(chipid));
660 
661 	aprint_normal_dev(self, "%s rev %d, Ethernet address %s\n",
662 	    sc->sc_variant->pcv_desc, CHIPID_VER(chipid),
663 	    ether_sprintf(enaddr));
664 
665 	/*
666 	 * VMware has a bug in its network interface emulation; we must
667 	 * limit the number of Tx segments.
668 	 */
669 	if (is_vmware) {
670 		ntxsegs = PCN_NTXSEGS_VMWARE;
671 		prop_dictionary_set_bool(device_properties(sc->sc_dev),
672 					 "am79c970-vmware-tx-bug", TRUE);
673 		aprint_verbose_dev(self,
674 		    "VMware Tx segment count bug detected\n");
675 	} else {
676 		ntxsegs = PCN_NTXSEGS;
677 	}
678 
679 	/*
680 	 * Map and establish our interrupt.
681 	 */
682 	if (pci_intr_map(pa, &ih)) {
683 		aprint_error_dev(self, "unable to map interrupt\n");
684 		return;
685 	}
686 	intrstr = pci_intr_string(pc, ih, intrbuf, sizeof(intrbuf));
687 	sc->sc_ih = pci_intr_establish(pc, ih, IPL_NET, pcn_intr, sc);
688 	if (sc->sc_ih == NULL) {
689 		aprint_error_dev(self, "unable to establish interrupt");
690 		if (intrstr != NULL)
691 			aprint_error(" at %s", intrstr);
692 		aprint_error("\n");
693 		return;
694 	}
695 	aprint_normal_dev(self, "interrupting at %s\n", intrstr);
696 
697 	/*
698 	 * Allocate the control data structures, and create and load the
699 	 * DMA map for it.
700 	 */
701 	if ((error = bus_dmamem_alloc(sc->sc_dmat,
702 	     sizeof(struct pcn_control_data), PAGE_SIZE, 0, &seg, 1, &rseg,
703 	     0)) != 0) {
704 		aprint_error_dev(self, "unable to allocate control data, "
705 		    "error = %d\n", error);
706 		goto fail_0;
707 	}
708 
709 	if ((error = bus_dmamem_map(sc->sc_dmat, &seg, rseg,
710 	     sizeof(struct pcn_control_data), (void **)&sc->sc_control_data,
711 	     BUS_DMA_COHERENT)) != 0) {
712 		aprint_error_dev(self, "unable to map control data, "
713 		    "error = %d\n", error);
714 		goto fail_1;
715 	}
716 
717 	if ((error = bus_dmamap_create(sc->sc_dmat,
718 	     sizeof(struct pcn_control_data), 1,
719 	     sizeof(struct pcn_control_data), 0, 0, &sc->sc_cddmamap)) != 0) {
720 		aprint_error_dev(self, "unable to create control data DMA map, "
721 		    "error = %d\n", error);
722 		goto fail_2;
723 	}
724 
725 	if ((error = bus_dmamap_load(sc->sc_dmat, sc->sc_cddmamap,
726 	     sc->sc_control_data, sizeof(struct pcn_control_data), NULL,
727 	     0)) != 0) {
728 		aprint_error_dev(self,
729 		    "unable to load control data DMA map, error = %d\n", error);
730 		goto fail_3;
731 	}
732 
733 	/* Create the transmit buffer DMA maps. */
734 	for (i = 0; i < PCN_TXQUEUELEN; i++) {
735 		if ((error = bus_dmamap_create(sc->sc_dmat, MCLBYTES,
736 		     ntxsegs, MCLBYTES, 0, 0,
737 		     &sc->sc_txsoft[i].txs_dmamap)) != 0) {
738 			aprint_error_dev(self,
739 			    "unable to create tx DMA map %d, error = %d\n",
740 			    i, error);
741 			goto fail_4;
742 		}
743 	}
744 
745 	/* Create the receive buffer DMA maps. */
746 	for (i = 0; i < PCN_NRXDESC; i++) {
747 		if ((error = bus_dmamap_create(sc->sc_dmat, MCLBYTES, 1,
748 		     MCLBYTES, 0, 0, &sc->sc_rxsoft[i].rxs_dmamap)) != 0) {
749 			aprint_error_dev(self,
750 			    "unable to create rx DMA map %d, error = %d\n",
751 			    i, error);
752 			goto fail_5;
753 		}
754 		sc->sc_rxsoft[i].rxs_mbuf = NULL;
755 	}
756 
757 	/* Initialize our media structures. */
758 	(*sc->sc_variant->pcv_mediainit)(sc);
759 
760 	/*
761 	 * Initialize FIFO watermark info.
762 	 */
763 	switch (sc->sc_variant->pcv_chipid) {
764 	case PARTID_Am79c970:
765 	case PARTID_Am79c970A:
766 		sc->sc_rcvfw_desc = pcn_79c970_rcvfw;
767 		sc->sc_xmtsp_desc = pcn_79c970_xmtsp;
768 		sc->sc_xmtfw_desc = pcn_79c970_xmtfw;
769 		break;
770 
771 	default:
772 		sc->sc_rcvfw_desc = pcn_79c971_rcvfw;
773 		/*
774 		 * Read BCR25 to determine how much SRAM is
775 		 * on the board.  If > 0, then we the chip
776 		 * uses different Start Point thresholds.
777 		 *
778 		 * Note BCR25 and BCR26 are loaded from the
779 		 * EEPROM on RST, and unaffected by S_RESET,
780 		 * so we don't really have to worry about
781 		 * them except for this.
782 		 */
783 		reg = pcn_bcr_read(sc, LE_BCR25) & 0x00ff;
784 		if (reg != 0)
785 			sc->sc_xmtsp_desc = pcn_79c971_xmtsp_sram;
786 		else
787 			sc->sc_xmtsp_desc = pcn_79c971_xmtsp;
788 		sc->sc_xmtfw_desc = pcn_79c971_xmtfw;
789 		break;
790 	}
791 
792 	/*
793 	 * Set up defaults -- see the tables above for what these
794 	 * values mean.
795 	 *
796 	 * XXX How should we tune RCVFW and XMTFW?
797 	 */
798 	sc->sc_rcvfw = 1;	/* minimum for full-duplex */
799 	sc->sc_xmtsp = 1;
800 	sc->sc_xmtfw = 0;
801 
802 	ifp = &sc->sc_ethercom.ec_if;
803 	strcpy(ifp->if_xname, device_xname(self));
804 	ifp->if_softc = sc;
805 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
806 	ifp->if_ioctl = pcn_ioctl;
807 	ifp->if_start = pcn_start;
808 	ifp->if_watchdog = pcn_watchdog;
809 	ifp->if_init = pcn_init;
810 	ifp->if_stop = pcn_stop;
811 	IFQ_SET_READY(&ifp->if_snd);
812 
813 	/* Attach the interface. */
814 	if_attach(ifp);
815 	if_deferred_start_init(ifp, NULL);
816 	ether_ifattach(ifp, enaddr);
817 	rnd_attach_source(&sc->rnd_source, device_xname(self),
818 	    RND_TYPE_NET, RND_FLAG_DEFAULT);
819 
820 #ifdef PCN_EVENT_COUNTERS
821 	/* Attach event counters. */
822 	evcnt_attach_dynamic(&sc->sc_ev_txsstall, EVCNT_TYPE_MISC,
823 	    NULL, device_xname(self), "txsstall");
824 	evcnt_attach_dynamic(&sc->sc_ev_txdstall, EVCNT_TYPE_MISC,
825 	    NULL, device_xname(self), "txdstall");
826 	evcnt_attach_dynamic(&sc->sc_ev_txintr, EVCNT_TYPE_INTR,
827 	    NULL, device_xname(self), "txintr");
828 	evcnt_attach_dynamic(&sc->sc_ev_rxintr, EVCNT_TYPE_INTR,
829 	    NULL, device_xname(self), "rxintr");
830 	evcnt_attach_dynamic(&sc->sc_ev_babl, EVCNT_TYPE_MISC,
831 	    NULL, device_xname(self), "babl");
832 	evcnt_attach_dynamic(&sc->sc_ev_miss, EVCNT_TYPE_MISC,
833 	    NULL, device_xname(self), "miss");
834 	evcnt_attach_dynamic(&sc->sc_ev_merr, EVCNT_TYPE_MISC,
835 	    NULL, device_xname(self), "merr");
836 
837 	evcnt_attach_dynamic(&sc->sc_ev_txseg1, EVCNT_TYPE_MISC,
838 	    NULL, device_xname(self), "txseg1");
839 	evcnt_attach_dynamic(&sc->sc_ev_txseg2, EVCNT_TYPE_MISC,
840 	    NULL, device_xname(self), "txseg2");
841 	evcnt_attach_dynamic(&sc->sc_ev_txseg3, EVCNT_TYPE_MISC,
842 	    NULL, device_xname(self), "txseg3");
843 	evcnt_attach_dynamic(&sc->sc_ev_txseg4, EVCNT_TYPE_MISC,
844 	    NULL, device_xname(self), "txseg4");
845 	evcnt_attach_dynamic(&sc->sc_ev_txseg5, EVCNT_TYPE_MISC,
846 	    NULL, device_xname(self), "txseg5");
847 	evcnt_attach_dynamic(&sc->sc_ev_txsegmore, EVCNT_TYPE_MISC,
848 	    NULL, device_xname(self), "txsegmore");
849 	evcnt_attach_dynamic(&sc->sc_ev_txcopy, EVCNT_TYPE_MISC,
850 	    NULL, device_xname(self), "txcopy");
851 #endif /* PCN_EVENT_COUNTERS */
852 
853 	/*
854 	 * Establish power handler with shutdown hook, to make sure
855 	 * the interface is shutdown during reboot.
856 	 */
857 	if (pmf_device_register1(self, NULL, NULL, pcn_shutdown))
858 		pmf_class_network_register(self, ifp);
859 	else
860 		aprint_error_dev(self, "couldn't establish power handler\n");
861 
862 	return;
863 
864 	/*
865 	 * Free any resources we've allocated during the failed attach
866 	 * attempt.  Do this in reverse order and fall through.
867 	 */
868  fail_5:
869 	for (i = 0; i < PCN_NRXDESC; i++) {
870 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
871 			bus_dmamap_destroy(sc->sc_dmat,
872 			    sc->sc_rxsoft[i].rxs_dmamap);
873 	}
874  fail_4:
875 	for (i = 0; i < PCN_TXQUEUELEN; i++) {
876 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
877 			bus_dmamap_destroy(sc->sc_dmat,
878 			    sc->sc_txsoft[i].txs_dmamap);
879 	}
880 	bus_dmamap_unload(sc->sc_dmat, sc->sc_cddmamap);
881  fail_3:
882 	bus_dmamap_destroy(sc->sc_dmat, sc->sc_cddmamap);
883  fail_2:
884 	bus_dmamem_unmap(sc->sc_dmat, (void *)sc->sc_control_data,
885 	    sizeof(struct pcn_control_data));
886  fail_1:
887 	bus_dmamem_free(sc->sc_dmat, &seg, rseg);
888  fail_0:
889 	return;
890 }
891 
892 /*
893  * pcn_shutdown:
894  *
895  *	Make sure the interface is stopped at reboot time.
896  */
897 static bool
898 pcn_shutdown(device_t self, int howto)
899 {
900 	struct pcn_softc *sc = device_private(self);
901 
902 	pcn_stop(&sc->sc_ethercom.ec_if, 1);
903 	/* explicitly reset the chip for some onboard one with lazy firmware */
904 	pcn_reset(sc);
905 
906 	return true;
907 }
908 
909 /*
910  * pcn_start:		[ifnet interface function]
911  *
912  *	Start packet transmission on the interface.
913  */
914 static void
915 pcn_start(struct ifnet *ifp)
916 {
917 	struct pcn_softc *sc = ifp->if_softc;
918 	struct mbuf *m0, *m;
919 	struct pcn_txsoft *txs;
920 	bus_dmamap_t dmamap;
921 	int error, nexttx, lasttx = -1, ofree, seg;
922 
923 	if ((ifp->if_flags & (IFF_RUNNING|IFF_OACTIVE)) != IFF_RUNNING)
924 		return;
925 
926 	/*
927 	 * Remember the previous number of free descriptors and
928 	 * the first descriptor we'll use.
929 	 */
930 	ofree = sc->sc_txfree;
931 
932 	/*
933 	 * Loop through the send queue, setting up transmit descriptors
934 	 * until we drain the queue, or use up all available transmit
935 	 * descriptors.
936 	 */
937 	for (;;) {
938 		/* Grab a packet off the queue. */
939 		IFQ_POLL(&ifp->if_snd, m0);
940 		if (m0 == NULL)
941 			break;
942 		m = NULL;
943 
944 		/* Get a work queue entry. */
945 		if (sc->sc_txsfree == 0) {
946 			PCN_EVCNT_INCR(&sc->sc_ev_txsstall);
947 			break;
948 		}
949 
950 		txs = &sc->sc_txsoft[sc->sc_txsnext];
951 		dmamap = txs->txs_dmamap;
952 
953 		/*
954 		 * Load the DMA map.  If this fails, the packet either
955 		 * didn't fit in the alloted number of segments, or we
956 		 * were short on resources.  In this case, we'll copy
957 		 * and try again.
958 		 */
959 		if (bus_dmamap_load_mbuf(sc->sc_dmat, dmamap, m0,
960 		    BUS_DMA_WRITE|BUS_DMA_NOWAIT) != 0) {
961 			PCN_EVCNT_INCR(&sc->sc_ev_txcopy);
962 			MGETHDR(m, M_DONTWAIT, MT_DATA);
963 			if (m == NULL) {
964 				printf("%s: unable to allocate Tx mbuf\n",
965 				    device_xname(sc->sc_dev));
966 				break;
967 			}
968 			if (m0->m_pkthdr.len > MHLEN) {
969 				MCLGET(m, M_DONTWAIT);
970 				if ((m->m_flags & M_EXT) == 0) {
971 					printf("%s: unable to allocate Tx "
972 					    "cluster\n",
973 					    device_xname(sc->sc_dev));
974 					m_freem(m);
975 					break;
976 				}
977 			}
978 			m_copydata(m0, 0, m0->m_pkthdr.len, mtod(m, void *));
979 			m->m_pkthdr.len = m->m_len = m0->m_pkthdr.len;
980 			error = bus_dmamap_load_mbuf(sc->sc_dmat, dmamap,
981 			    m, BUS_DMA_WRITE|BUS_DMA_NOWAIT);
982 			if (error) {
983 				printf("%s: unable to load Tx buffer, "
984 				    "error = %d\n", device_xname(sc->sc_dev),
985 				    error);
986 				m_freem(m);
987 				break;
988 			}
989 		}
990 
991 		/*
992 		 * Ensure we have enough descriptors free to describe
993 		 * the packet.  Note, we always reserve one descriptor
994 		 * at the end of the ring as a termination point, to
995 		 * prevent wrap-around.
996 		 */
997 		if (dmamap->dm_nsegs > (sc->sc_txfree - 1)) {
998 			/*
999 			 * Not enough free descriptors to transmit this
1000 			 * packet.  We haven't committed anything yet,
1001 			 * so just unload the DMA map, put the packet
1002 			 * back on the queue, and punt.  Notify the upper
1003 			 * layer that there are not more slots left.
1004 			 *
1005 			 * XXX We could allocate an mbuf and copy, but
1006 			 * XXX is it worth it?
1007 			 */
1008 			ifp->if_flags |= IFF_OACTIVE;
1009 			bus_dmamap_unload(sc->sc_dmat, dmamap);
1010 			if (m != NULL)
1011 				m_freem(m);
1012 			PCN_EVCNT_INCR(&sc->sc_ev_txdstall);
1013 			break;
1014 		}
1015 
1016 		IFQ_DEQUEUE(&ifp->if_snd, m0);
1017 		if (m != NULL) {
1018 			m_freem(m0);
1019 			m0 = m;
1020 		}
1021 
1022 		/*
1023 		 * WE ARE NOW COMMITTED TO TRANSMITTING THE PACKET.
1024 		 */
1025 
1026 		/* Sync the DMA map. */
1027 		bus_dmamap_sync(sc->sc_dmat, dmamap, 0, dmamap->dm_mapsize,
1028 		    BUS_DMASYNC_PREWRITE);
1029 
1030 #ifdef PCN_EVENT_COUNTERS
1031 		switch (dmamap->dm_nsegs) {
1032 		case 1:
1033 			PCN_EVCNT_INCR(&sc->sc_ev_txseg1);
1034 			break;
1035 		case 2:
1036 			PCN_EVCNT_INCR(&sc->sc_ev_txseg2);
1037 			break;
1038 		case 3:
1039 			PCN_EVCNT_INCR(&sc->sc_ev_txseg3);
1040 			break;
1041 		case 4:
1042 			PCN_EVCNT_INCR(&sc->sc_ev_txseg4);
1043 			break;
1044 		case 5:
1045 			PCN_EVCNT_INCR(&sc->sc_ev_txseg5);
1046 			break;
1047 		default:
1048 			PCN_EVCNT_INCR(&sc->sc_ev_txsegmore);
1049 			break;
1050 		}
1051 #endif /* PCN_EVENT_COUNTERS */
1052 
1053 		/*
1054 		 * Initialize the transmit descriptors.
1055 		 */
1056 		if (sc->sc_swstyle == LE_B20_SSTYLE_PCNETPCI3) {
1057 			for (nexttx = sc->sc_txnext, seg = 0;
1058 			     seg < dmamap->dm_nsegs;
1059 			     seg++, nexttx = PCN_NEXTTX(nexttx)) {
1060 				/*
1061 				 * If this is the first descriptor we're
1062 				 * enqueueing, don't set the OWN bit just
1063 				 * yet.  That could cause a race condition.
1064 				 * We'll do it below.
1065 				 */
1066 				sc->sc_txdescs[nexttx].tmd0 = 0;
1067 				sc->sc_txdescs[nexttx].tmd2 =
1068 				    htole32(dmamap->dm_segs[seg].ds_addr);
1069 				sc->sc_txdescs[nexttx].tmd1 =
1070 				    htole32(LE_T1_ONES |
1071 				    (nexttx == sc->sc_txnext ? 0 : LE_T1_OWN) |
1072 				    (LE_BCNT(dmamap->dm_segs[seg].ds_len) &
1073 				     LE_T1_BCNT_MASK));
1074 				lasttx = nexttx;
1075 			}
1076 		} else {
1077 			for (nexttx = sc->sc_txnext, seg = 0;
1078 			     seg < dmamap->dm_nsegs;
1079 			     seg++, nexttx = PCN_NEXTTX(nexttx)) {
1080 				/*
1081 				 * If this is the first descriptor we're
1082 				 * enqueueing, don't set the OWN bit just
1083 				 * yet.  That could cause a race condition.
1084 				 * We'll do it below.
1085 				 */
1086 				sc->sc_txdescs[nexttx].tmd0 =
1087 				    htole32(dmamap->dm_segs[seg].ds_addr);
1088 				sc->sc_txdescs[nexttx].tmd2 = 0;
1089 				sc->sc_txdescs[nexttx].tmd1 =
1090 				    htole32(LE_T1_ONES |
1091 				    (nexttx == sc->sc_txnext ? 0 : LE_T1_OWN) |
1092 				    (LE_BCNT(dmamap->dm_segs[seg].ds_len) &
1093 				     LE_T1_BCNT_MASK));
1094 				lasttx = nexttx;
1095 			}
1096 		}
1097 
1098 		KASSERT(lasttx != -1);
1099 		/* Interrupt on the packet, if appropriate. */
1100 		if ((sc->sc_txsnext & PCN_TXINTR_MASK) == 0)
1101 			sc->sc_txdescs[lasttx].tmd1 |= htole32(LE_T1_LTINT);
1102 
1103 		/* Set `start of packet' and `end of packet' appropriately. */
1104 		sc->sc_txdescs[lasttx].tmd1 |= htole32(LE_T1_ENP);
1105 		sc->sc_txdescs[sc->sc_txnext].tmd1 |=
1106 		    htole32(LE_T1_OWN|LE_T1_STP);
1107 
1108 		/* Sync the descriptors we're using. */
1109 		PCN_CDTXSYNC(sc, sc->sc_txnext, dmamap->dm_nsegs,
1110 		    BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
1111 
1112 		/* Kick the transmitter. */
1113 		pcn_csr_write(sc, LE_CSR0, LE_C0_INEA|LE_C0_TDMD);
1114 
1115 		/*
1116 		 * Store a pointer to the packet so we can free it later,
1117 		 * and remember what txdirty will be once the packet is
1118 		 * done.
1119 		 */
1120 		txs->txs_mbuf = m0;
1121 		txs->txs_firstdesc = sc->sc_txnext;
1122 		txs->txs_lastdesc = lasttx;
1123 
1124 		/* Advance the tx pointer. */
1125 		sc->sc_txfree -= dmamap->dm_nsegs;
1126 		sc->sc_txnext = nexttx;
1127 
1128 		sc->sc_txsfree--;
1129 		sc->sc_txsnext = PCN_NEXTTXS(sc->sc_txsnext);
1130 
1131 		/* Pass the packet to any BPF listeners. */
1132 		bpf_mtap(ifp, m0, BPF_D_OUT);
1133 	}
1134 
1135 	if (sc->sc_txsfree == 0 || sc->sc_txfree == 0) {
1136 		/* No more slots left; notify upper layer. */
1137 		ifp->if_flags |= IFF_OACTIVE;
1138 	}
1139 
1140 	if (sc->sc_txfree != ofree) {
1141 		/* Set a watchdog timer in case the chip flakes out. */
1142 		ifp->if_timer = 5;
1143 	}
1144 }
1145 
1146 /*
1147  * pcn_watchdog:	[ifnet interface function]
1148  *
1149  *	Watchdog timer handler.
1150  */
1151 static void
1152 pcn_watchdog(struct ifnet *ifp)
1153 {
1154 	struct pcn_softc *sc = ifp->if_softc;
1155 
1156 	/*
1157 	 * Since we're not interrupting every packet, sweep
1158 	 * up before we report an error.
1159 	 */
1160 	pcn_txintr(sc);
1161 
1162 	if (sc->sc_txfree != PCN_NTXDESC) {
1163 		printf("%s: device timeout (txfree %d txsfree %d)\n",
1164 		    device_xname(sc->sc_dev), sc->sc_txfree, sc->sc_txsfree);
1165 		ifp->if_oerrors++;
1166 
1167 		/* Reset the interface. */
1168 		(void) pcn_init(ifp);
1169 	}
1170 
1171 	/* Try to get more packets going. */
1172 	pcn_start(ifp);
1173 }
1174 
1175 /*
1176  * pcn_ioctl:		[ifnet interface function]
1177  *
1178  *	Handle control requests from the operator.
1179  */
1180 static int
1181 pcn_ioctl(struct ifnet *ifp, u_long cmd, void *data)
1182 {
1183 	struct pcn_softc *sc = ifp->if_softc;
1184 	struct ifreq *ifr = (struct ifreq *) data;
1185 	int s, error;
1186 
1187 	s = splnet();
1188 
1189 	switch (cmd) {
1190 	case SIOCSIFMEDIA:
1191 	case SIOCGIFMEDIA:
1192 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_mii.mii_media, cmd);
1193 		break;
1194 
1195 	default:
1196 		error = ether_ioctl(ifp, cmd, data);
1197 		if (error == ENETRESET) {
1198 			/*
1199 			 * Multicast list has changed; set the hardware filter
1200 			 * accordingly.
1201 			 */
1202 			if (ifp->if_flags & IFF_RUNNING)
1203 				error = pcn_init(ifp);
1204 			else
1205 				error = 0;
1206 		}
1207 		break;
1208 	}
1209 
1210 	/* Try to get more packets going. */
1211 	pcn_start(ifp);
1212 
1213 	splx(s);
1214 	return (error);
1215 }
1216 
1217 /*
1218  * pcn_intr:
1219  *
1220  *	Interrupt service routine.
1221  */
1222 static int
1223 pcn_intr(void *arg)
1224 {
1225 	struct pcn_softc *sc = arg;
1226 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
1227 	uint32_t csr0;
1228 	int wantinit, handled = 0;
1229 
1230 	for (wantinit = 0; wantinit == 0;) {
1231 		csr0 = pcn_csr_read(sc, LE_CSR0);
1232 		if ((csr0 & LE_C0_INTR) == 0)
1233 			break;
1234 
1235 		rnd_add_uint32(&sc->rnd_source, csr0);
1236 
1237 		/* ACK the bits and re-enable interrupts. */
1238 		pcn_csr_write(sc, LE_CSR0, csr0 &
1239 		    (LE_C0_INEA|LE_C0_BABL|LE_C0_MISS|LE_C0_MERR|LE_C0_RINT|
1240 		     LE_C0_TINT|LE_C0_IDON));
1241 
1242 		handled = 1;
1243 
1244 		if (csr0 & LE_C0_RINT) {
1245 			PCN_EVCNT_INCR(&sc->sc_ev_rxintr);
1246 			wantinit = pcn_rxintr(sc);
1247 		}
1248 
1249 		if (csr0 & LE_C0_TINT) {
1250 			PCN_EVCNT_INCR(&sc->sc_ev_txintr);
1251 			pcn_txintr(sc);
1252 		}
1253 
1254 		if (csr0 & LE_C0_ERR) {
1255 			if (csr0 & LE_C0_BABL) {
1256 				PCN_EVCNT_INCR(&sc->sc_ev_babl);
1257 				ifp->if_oerrors++;
1258 			}
1259 			if (csr0 & LE_C0_MISS) {
1260 				PCN_EVCNT_INCR(&sc->sc_ev_miss);
1261 				ifp->if_ierrors++;
1262 			}
1263 			if (csr0 & LE_C0_MERR) {
1264 				PCN_EVCNT_INCR(&sc->sc_ev_merr);
1265 				printf("%s: memory error\n",
1266 				    device_xname(sc->sc_dev));
1267 				wantinit = 1;
1268 				break;
1269 			}
1270 		}
1271 
1272 		if ((csr0 & LE_C0_RXON) == 0) {
1273 			printf("%s: receiver disabled\n",
1274 			    device_xname(sc->sc_dev));
1275 			ifp->if_ierrors++;
1276 			wantinit = 1;
1277 		}
1278 
1279 		if ((csr0 & LE_C0_TXON) == 0) {
1280 			printf("%s: transmitter disabled\n",
1281 			    device_xname(sc->sc_dev));
1282 			ifp->if_oerrors++;
1283 			wantinit = 1;
1284 		}
1285 	}
1286 
1287 	if (handled) {
1288 		if (wantinit)
1289 			pcn_init(ifp);
1290 
1291 		/* Try to get more packets going. */
1292 		if_schedule_deferred_start(ifp);
1293 	}
1294 
1295 	return (handled);
1296 }
1297 
1298 /*
1299  * pcn_spnd:
1300  *
1301  *	Suspend the chip.
1302  */
1303 static void
1304 pcn_spnd(struct pcn_softc *sc)
1305 {
1306 	int i;
1307 
1308 	pcn_csr_write(sc, LE_CSR5, sc->sc_csr5 | LE_C5_SPND);
1309 
1310 	for (i = 0; i < 10000; i++) {
1311 		if (pcn_csr_read(sc, LE_CSR5) & LE_C5_SPND)
1312 			return;
1313 		delay(5);
1314 	}
1315 
1316 	printf("%s: WARNING: chip failed to enter suspended state\n",
1317 	    device_xname(sc->sc_dev));
1318 }
1319 
1320 /*
1321  * pcn_txintr:
1322  *
1323  *	Helper; handle transmit interrupts.
1324  */
1325 static void
1326 pcn_txintr(struct pcn_softc *sc)
1327 {
1328 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
1329 	struct pcn_txsoft *txs;
1330 	uint32_t tmd1, tmd2, tmd;
1331 	int i, j;
1332 
1333 	ifp->if_flags &= ~IFF_OACTIVE;
1334 
1335 	/*
1336 	 * Go through our Tx list and free mbufs for those
1337 	 * frames which have been transmitted.
1338 	 */
1339 	for (i = sc->sc_txsdirty; sc->sc_txsfree != PCN_TXQUEUELEN;
1340 	     i = PCN_NEXTTXS(i), sc->sc_txsfree++) {
1341 		txs = &sc->sc_txsoft[i];
1342 
1343 		PCN_CDTXSYNC(sc, txs->txs_firstdesc, txs->txs_dmamap->dm_nsegs,
1344 		    BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
1345 
1346 		tmd1 = le32toh(sc->sc_txdescs[txs->txs_lastdesc].tmd1);
1347 		if (tmd1 & LE_T1_OWN)
1348 			break;
1349 
1350 		/*
1351 		 * Slightly annoying -- we have to loop through the
1352 		 * descriptors we've used looking for ERR, since it
1353 		 * can appear on any descriptor in the chain.
1354 		 */
1355 		for (j = txs->txs_firstdesc;; j = PCN_NEXTTX(j)) {
1356 			tmd = le32toh(sc->sc_txdescs[j].tmd1);
1357 			if (tmd & LE_T1_ERR) {
1358 				ifp->if_oerrors++;
1359 				if (sc->sc_swstyle == LE_B20_SSTYLE_PCNETPCI3)
1360 					tmd2 = le32toh(sc->sc_txdescs[j].tmd0);
1361 				else
1362 					tmd2 = le32toh(sc->sc_txdescs[j].tmd2);
1363 				if (tmd2 & LE_T2_UFLO) {
1364 					if (sc->sc_xmtsp < LE_C80_XMTSP_MAX) {
1365 						sc->sc_xmtsp++;
1366 						printf("%s: transmit "
1367 						    "underrun; new threshold: "
1368 						    "%s\n",
1369 						    device_xname(sc->sc_dev),
1370 						    sc->sc_xmtsp_desc[
1371 						    sc->sc_xmtsp]);
1372 						pcn_spnd(sc);
1373 						pcn_csr_write(sc, LE_CSR80,
1374 						    LE_C80_RCVFW(sc->sc_rcvfw) |
1375 						    LE_C80_XMTSP(sc->sc_xmtsp) |
1376 						    LE_C80_XMTFW(sc->sc_xmtfw));
1377 						pcn_csr_write(sc, LE_CSR5,
1378 						    sc->sc_csr5);
1379 					} else {
1380 						printf("%s: transmit "
1381 						    "underrun\n",
1382 						    device_xname(sc->sc_dev));
1383 					}
1384 				} else if (tmd2 & LE_T2_BUFF) {
1385 					printf("%s: transmit buffer error\n",
1386 					    device_xname(sc->sc_dev));
1387 				}
1388 				if (tmd2 & LE_T2_LCOL)
1389 					ifp->if_collisions++;
1390 				if (tmd2 & LE_T2_RTRY)
1391 					ifp->if_collisions += 16;
1392 				goto next_packet;
1393 			}
1394 			if (j == txs->txs_lastdesc)
1395 				break;
1396 		}
1397 		if (tmd1 & LE_T1_ONE)
1398 			ifp->if_collisions++;
1399 		else if (tmd & LE_T1_MORE) {
1400 			/* Real number is unknown. */
1401 			ifp->if_collisions += 2;
1402 		}
1403 		ifp->if_opackets++;
1404  next_packet:
1405 		sc->sc_txfree += txs->txs_dmamap->dm_nsegs;
1406 		bus_dmamap_sync(sc->sc_dmat, txs->txs_dmamap,
1407 		    0, txs->txs_dmamap->dm_mapsize, BUS_DMASYNC_POSTWRITE);
1408 		bus_dmamap_unload(sc->sc_dmat, txs->txs_dmamap);
1409 		m_freem(txs->txs_mbuf);
1410 		txs->txs_mbuf = NULL;
1411 	}
1412 
1413 	/* Update the dirty transmit buffer pointer. */
1414 	sc->sc_txsdirty = i;
1415 
1416 	/*
1417 	 * If there are no more pending transmissions, cancel the watchdog
1418 	 * timer.
1419 	 */
1420 	if (sc->sc_txsfree == PCN_TXQUEUELEN)
1421 		ifp->if_timer = 0;
1422 }
1423 
1424 /*
1425  * pcn_rxintr:
1426  *
1427  *	Helper; handle receive interrupts.
1428  */
1429 static int
1430 pcn_rxintr(struct pcn_softc *sc)
1431 {
1432 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
1433 	struct pcn_rxsoft *rxs;
1434 	struct mbuf *m;
1435 	uint32_t rmd1;
1436 	int i, len;
1437 
1438 	for (i = sc->sc_rxptr;; i = PCN_NEXTRX(i)) {
1439 		rxs = &sc->sc_rxsoft[i];
1440 
1441 		PCN_CDRXSYNC(sc, i, BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
1442 
1443 		rmd1 = le32toh(sc->sc_rxdescs[i].rmd1);
1444 
1445 		if (rmd1 & LE_R1_OWN)
1446 			break;
1447 
1448 		/*
1449 		 * Check for errors and make sure the packet fit into
1450 		 * a single buffer.  We have structured this block of
1451 		 * code the way it is in order to compress it into
1452 		 * one test in the common case (no error).
1453 		 */
1454 		if (__predict_false((rmd1 & (LE_R1_STP|LE_R1_ENP|LE_R1_ERR)) !=
1455 		    (LE_R1_STP|LE_R1_ENP))) {
1456 			/* Make sure the packet is in a single buffer. */
1457 			if ((rmd1 & (LE_R1_STP|LE_R1_ENP)) !=
1458 			    (LE_R1_STP|LE_R1_ENP)) {
1459 				printf("%s: packet spilled into next buffer\n",
1460 				    device_xname(sc->sc_dev));
1461 				return (1);	/* pcn_intr() will re-init */
1462 			}
1463 
1464 			/*
1465 			 * If the packet had an error, simple recycle the
1466 			 * buffer.
1467 			 */
1468 			if (rmd1 & LE_R1_ERR) {
1469 				ifp->if_ierrors++;
1470 				/*
1471 				 * If we got an overflow error, chances
1472 				 * are there will be a CRC error.  In
1473 				 * this case, just print the overflow
1474 				 * error, and skip the others.
1475 				 */
1476 				if (rmd1 & LE_R1_OFLO)
1477 					printf("%s: overflow error\n",
1478 					    device_xname(sc->sc_dev));
1479 				else {
1480 #define	PRINTIT(x, str)							\
1481 					if (rmd1 & (x))			\
1482 						printf("%s: %s\n",	\
1483 						    device_xname(sc->sc_dev), \
1484 						    str);
1485 					PRINTIT(LE_R1_FRAM, "framing error");
1486 					PRINTIT(LE_R1_CRC, "CRC error");
1487 					PRINTIT(LE_R1_BUFF, "buffer error");
1488 				}
1489 #undef PRINTIT
1490 				PCN_INIT_RXDESC(sc, i);
1491 				continue;
1492 			}
1493 		}
1494 
1495 		bus_dmamap_sync(sc->sc_dmat, rxs->rxs_dmamap, 0,
1496 		    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);
1497 
1498 		/*
1499 		 * No errors; receive the packet.
1500 		 */
1501 		if (sc->sc_swstyle == LE_B20_SSTYLE_PCNETPCI3)
1502 			len = le32toh(sc->sc_rxdescs[i].rmd0) & LE_R1_BCNT_MASK;
1503 		else
1504 			len = le32toh(sc->sc_rxdescs[i].rmd2) & LE_R1_BCNT_MASK;
1505 
1506 		/*
1507 		 * The LANCE family includes the CRC with every packet;
1508 		 * trim it off here.
1509 		 */
1510 		len -= ETHER_CRC_LEN;
1511 
1512 		/*
1513 		 * If the packet is small enough to fit in a
1514 		 * single header mbuf, allocate one and copy
1515 		 * the data into it.  This greatly reduces
1516 		 * memory consumption when we receive lots
1517 		 * of small packets.
1518 		 *
1519 		 * Otherwise, we add a new buffer to the receive
1520 		 * chain.  If this fails, we drop the packet and
1521 		 * recycle the old buffer.
1522 		 */
1523 		if (pcn_copy_small != 0 && len <= (MHLEN - 2)) {
1524 			MGETHDR(m, M_DONTWAIT, MT_DATA);
1525 			if (m == NULL)
1526 				goto dropit;
1527 			m->m_data += 2;
1528 			memcpy(mtod(m, void *),
1529 			    mtod(rxs->rxs_mbuf, void *), len);
1530 			PCN_INIT_RXDESC(sc, i);
1531 			bus_dmamap_sync(sc->sc_dmat, rxs->rxs_dmamap, 0,
1532 			    rxs->rxs_dmamap->dm_mapsize,
1533 			    BUS_DMASYNC_PREREAD);
1534 		} else {
1535 			m = rxs->rxs_mbuf;
1536 			if (pcn_add_rxbuf(sc, i) != 0) {
1537  dropit:
1538 				ifp->if_ierrors++;
1539 				PCN_INIT_RXDESC(sc, i);
1540 				bus_dmamap_sync(sc->sc_dmat,
1541 				    rxs->rxs_dmamap, 0,
1542 				    rxs->rxs_dmamap->dm_mapsize,
1543 				    BUS_DMASYNC_PREREAD);
1544 				continue;
1545 			}
1546 		}
1547 
1548 		m_set_rcvif(m, ifp);
1549 		m->m_pkthdr.len = m->m_len = len;
1550 
1551 		/* Pass it on. */
1552 		if_percpuq_enqueue(ifp->if_percpuq, m);
1553 	}
1554 
1555 	/* Update the receive pointer. */
1556 	sc->sc_rxptr = i;
1557 	return (0);
1558 }
1559 
1560 /*
1561  * pcn_tick:
1562  *
1563  *	One second timer, used to tick the MII.
1564  */
1565 static void
1566 pcn_tick(void *arg)
1567 {
1568 	struct pcn_softc *sc = arg;
1569 	int s;
1570 
1571 	s = splnet();
1572 	mii_tick(&sc->sc_mii);
1573 	splx(s);
1574 
1575 	callout_reset(&sc->sc_tick_ch, hz, pcn_tick, sc);
1576 }
1577 
1578 /*
1579  * pcn_reset:
1580  *
1581  *	Perform a soft reset on the PCnet-PCI.
1582  */
1583 static void
1584 pcn_reset(struct pcn_softc *sc)
1585 {
1586 
1587 	/*
1588 	 * The PCnet-PCI chip is reset by reading from the
1589 	 * RESET register.  Note that while the NE2100 LANCE
1590 	 * boards require a write after the read, the PCnet-PCI
1591 	 * chips do not require this.
1592 	 *
1593 	 * Since we don't know if we're in 16-bit or 32-bit
1594 	 * mode right now, issue both (it's safe) in the
1595 	 * hopes that one will succeed.
1596 	 */
1597 	(void) bus_space_read_2(sc->sc_st, sc->sc_sh, PCN16_RESET);
1598 	(void) bus_space_read_4(sc->sc_st, sc->sc_sh, PCN32_RESET);
1599 
1600 	/* Wait 1ms for it to finish. */
1601 	delay(1000);
1602 
1603 	/*
1604 	 * Select 32-bit I/O mode by issuing a 32-bit write to the
1605 	 * RDP.  Since the RAP is 0 after a reset, writing a 0
1606 	 * to RDP is safe (since it simply clears CSR0).
1607 	 */
1608 	bus_space_write_4(sc->sc_st, sc->sc_sh, PCN32_RDP, 0);
1609 }
1610 
1611 /*
1612  * pcn_init:		[ifnet interface function]
1613  *
1614  *	Initialize the interface.  Must be called at splnet().
1615  */
1616 static int
1617 pcn_init(struct ifnet *ifp)
1618 {
1619 	struct pcn_softc *sc = ifp->if_softc;
1620 	struct pcn_rxsoft *rxs;
1621 	const uint8_t *enaddr = CLLADDR(ifp->if_sadl);
1622 	int i, error = 0;
1623 	uint32_t reg;
1624 
1625 	/* Cancel any pending I/O. */
1626 	pcn_stop(ifp, 0);
1627 
1628 	/* Reset the chip to a known state. */
1629 	pcn_reset(sc);
1630 
1631 	/*
1632 	 * On the Am79c970, select SSTYLE 2, and SSTYLE 3 on everything
1633 	 * else.
1634 	 *
1635 	 * XXX It'd be really nice to use SSTYLE 2 on all the chips,
1636 	 * because the structure layout is compatible with ILACC,
1637 	 * but the burst mode is only available in SSTYLE 3, and
1638 	 * burst mode should provide some performance enhancement.
1639 	 */
1640 	if (sc->sc_variant->pcv_chipid == PARTID_Am79c970)
1641 		sc->sc_swstyle = LE_B20_SSTYLE_PCNETPCI2;
1642 	else
1643 		sc->sc_swstyle = LE_B20_SSTYLE_PCNETPCI3;
1644 	pcn_bcr_write(sc, LE_BCR20, sc->sc_swstyle);
1645 
1646 	/* Initialize the transmit descriptor ring. */
1647 	memset(sc->sc_txdescs, 0, sizeof(sc->sc_txdescs));
1648 	PCN_CDTXSYNC(sc, 0, PCN_NTXDESC,
1649 	    BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
1650 	sc->sc_txfree = PCN_NTXDESC;
1651 	sc->sc_txnext = 0;
1652 
1653 	/* Initialize the transmit job descriptors. */
1654 	for (i = 0; i < PCN_TXQUEUELEN; i++)
1655 		sc->sc_txsoft[i].txs_mbuf = NULL;
1656 	sc->sc_txsfree = PCN_TXQUEUELEN;
1657 	sc->sc_txsnext = 0;
1658 	sc->sc_txsdirty = 0;
1659 
1660 	/*
1661 	 * Initialize the receive descriptor and receive job
1662 	 * descriptor rings.
1663 	 */
1664 	for (i = 0; i < PCN_NRXDESC; i++) {
1665 		rxs = &sc->sc_rxsoft[i];
1666 		if (rxs->rxs_mbuf == NULL) {
1667 			if ((error = pcn_add_rxbuf(sc, i)) != 0) {
1668 				printf("%s: unable to allocate or map rx "
1669 				    "buffer %d, error = %d\n",
1670 				    device_xname(sc->sc_dev), i, error);
1671 				/*
1672 				 * XXX Should attempt to run with fewer receive
1673 				 * XXX buffers instead of just failing.
1674 				 */
1675 				pcn_rxdrain(sc);
1676 				goto out;
1677 			}
1678 		} else
1679 			PCN_INIT_RXDESC(sc, i);
1680 	}
1681 	sc->sc_rxptr = 0;
1682 
1683 	/* Initialize MODE for the initialization block. */
1684 	sc->sc_mode = 0;
1685 	if (ifp->if_flags & IFF_PROMISC)
1686 		sc->sc_mode |= LE_C15_PROM;
1687 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1688 		sc->sc_mode |= LE_C15_DRCVBC;
1689 
1690 	/*
1691 	 * If we have MII, simply select MII in the MODE register,
1692 	 * and clear ASEL.  Otherwise, let ASEL stand (for now),
1693 	 * and leave PORTSEL alone (it is ignored with ASEL is set).
1694 	 */
1695 	if (sc->sc_flags & PCN_F_HAS_MII) {
1696 		pcn_bcr_write(sc, LE_BCR2,
1697 		    pcn_bcr_read(sc, LE_BCR2) & ~LE_B2_ASEL);
1698 		sc->sc_mode |= LE_C15_PORTSEL(PORTSEL_MII);
1699 
1700 		/*
1701 		 * Disable MII auto-negotiation.  We handle that in
1702 		 * our own MII layer.
1703 		 */
1704 		pcn_bcr_write(sc, LE_BCR32,
1705 		    pcn_bcr_read(sc, LE_BCR32) | LE_B32_DANAS);
1706 	}
1707 
1708 	/*
1709 	 * Set the Tx and Rx descriptor ring addresses in the init
1710 	 * block, the TLEN and RLEN other fields of the init block
1711 	 * MODE register.
1712 	 */
1713 	sc->sc_initblock.init_rdra = htole32(PCN_CDRXADDR(sc, 0));
1714 	sc->sc_initblock.init_tdra = htole32(PCN_CDTXADDR(sc, 0));
1715 	sc->sc_initblock.init_mode = htole32(sc->sc_mode |
1716 	    ((ffs(PCN_NTXDESC) - 1) << 28) |
1717 	    ((ffs(PCN_NRXDESC) - 1) << 20));
1718 
1719 	/* Set the station address in the init block. */
1720 	sc->sc_initblock.init_padr[0] = htole32(enaddr[0] |
1721 	    (enaddr[1] << 8) | (enaddr[2] << 16) | (enaddr[3] << 24));
1722 	sc->sc_initblock.init_padr[1] = htole32(enaddr[4] |
1723 	    (enaddr[5] << 8));
1724 
1725 	/* Set the multicast filter in the init block. */
1726 	pcn_set_filter(sc);
1727 
1728 	/* Initialize CSR3. */
1729 	pcn_csr_write(sc, LE_CSR3, LE_C3_MISSM|LE_C3_IDONM|LE_C3_DXSUFLO);
1730 
1731 	/* Initialize CSR4. */
1732 	pcn_csr_write(sc, LE_CSR4, LE_C4_DMAPLUS|LE_C4_APAD_XMT|
1733 	    LE_C4_MFCOM|LE_C4_RCVCCOM|LE_C4_TXSTRTM);
1734 
1735 	/* Initialize CSR5. */
1736 	sc->sc_csr5 = LE_C5_LTINTEN|LE_C5_SINTE;
1737 	pcn_csr_write(sc, LE_CSR5, sc->sc_csr5);
1738 
1739 	/*
1740 	 * If we have an Am79c971 or greater, initialize CSR7.
1741 	 *
1742 	 * XXX Might be nice to use the MII auto-poll interrupt someday.
1743 	 */
1744 	switch (sc->sc_variant->pcv_chipid) {
1745 	case PARTID_Am79c970:
1746 	case PARTID_Am79c970A:
1747 		/* Not available on these chips. */
1748 		break;
1749 
1750 	default:
1751 		pcn_csr_write(sc, LE_CSR7, LE_C7_FASTSPNDE);
1752 		break;
1753 	}
1754 
1755 	/*
1756 	 * On the Am79c970A and greater, initialize BCR18 to
1757 	 * enable burst mode.
1758 	 *
1759 	 * Also enable the "no underflow" option on the Am79c971 and
1760 	 * higher, which prevents the chip from generating transmit
1761 	 * underflows, yet sill provides decent performance.  Note if
1762 	 * chip is not connected to external SRAM, then we still have
1763 	 * to handle underflow errors (the NOUFLO bit is ignored in
1764 	 * that case).
1765 	 */
1766 	reg = pcn_bcr_read(sc, LE_BCR18);
1767 	switch (sc->sc_variant->pcv_chipid) {
1768 	case PARTID_Am79c970:
1769 		break;
1770 
1771 	case PARTID_Am79c970A:
1772 		reg |= LE_B18_BREADE|LE_B18_BWRITE;
1773 		break;
1774 
1775 	default:
1776 		reg |= LE_B18_BREADE|LE_B18_BWRITE|LE_B18_NOUFLO;
1777 		break;
1778 	}
1779 	pcn_bcr_write(sc, LE_BCR18, reg);
1780 
1781 	/*
1782 	 * Initialize CSR80 (FIFO thresholds for Tx and Rx).
1783 	 */
1784 	pcn_csr_write(sc, LE_CSR80, LE_C80_RCVFW(sc->sc_rcvfw) |
1785 	    LE_C80_XMTSP(sc->sc_xmtsp) | LE_C80_XMTFW(sc->sc_xmtfw));
1786 
1787 	/*
1788 	 * Send the init block to the chip, and wait for it
1789 	 * to be processed.
1790 	 */
1791 	PCN_CDINITSYNC(sc, BUS_DMASYNC_PREWRITE);
1792 	pcn_csr_write(sc, LE_CSR1, PCN_CDINITADDR(sc) & 0xffff);
1793 	pcn_csr_write(sc, LE_CSR2, (PCN_CDINITADDR(sc) >> 16) & 0xffff);
1794 	pcn_csr_write(sc, LE_CSR0, LE_C0_INIT);
1795 	delay(100);
1796 	for (i = 0; i < 10000; i++) {
1797 		if (pcn_csr_read(sc, LE_CSR0) & LE_C0_IDON)
1798 			break;
1799 		delay(10);
1800 	}
1801 	PCN_CDINITSYNC(sc, BUS_DMASYNC_POSTWRITE);
1802 	if (i == 10000) {
1803 		printf("%s: timeout processing init block\n",
1804 		    device_xname(sc->sc_dev));
1805 		error = EIO;
1806 		goto out;
1807 	}
1808 
1809 	/* Set the media. */
1810 	if ((error = mii_ifmedia_change(&sc->sc_mii)) != 0)
1811 		goto out;
1812 
1813 	/* Enable interrupts and external activity (and ACK IDON). */
1814 	pcn_csr_write(sc, LE_CSR0, LE_C0_INEA|LE_C0_STRT|LE_C0_IDON);
1815 
1816 	if (sc->sc_flags & PCN_F_HAS_MII) {
1817 		/* Start the one second MII clock. */
1818 		callout_reset(&sc->sc_tick_ch, hz, pcn_tick, sc);
1819 	}
1820 
1821 	/* ...all done! */
1822 	ifp->if_flags |= IFF_RUNNING;
1823 	ifp->if_flags &= ~IFF_OACTIVE;
1824 
1825  out:
1826 	if (error)
1827 		printf("%s: interface not running\n", device_xname(sc->sc_dev));
1828 	return (error);
1829 }
1830 
1831 /*
1832  * pcn_rxdrain:
1833  *
1834  *	Drain the receive queue.
1835  */
1836 static void
1837 pcn_rxdrain(struct pcn_softc *sc)
1838 {
1839 	struct pcn_rxsoft *rxs;
1840 	int i;
1841 
1842 	for (i = 0; i < PCN_NRXDESC; i++) {
1843 		rxs = &sc->sc_rxsoft[i];
1844 		if (rxs->rxs_mbuf != NULL) {
1845 			bus_dmamap_unload(sc->sc_dmat, rxs->rxs_dmamap);
1846 			m_freem(rxs->rxs_mbuf);
1847 			rxs->rxs_mbuf = NULL;
1848 		}
1849 	}
1850 }
1851 
1852 /*
1853  * pcn_stop:		[ifnet interface function]
1854  *
1855  *	Stop transmission on the interface.
1856  */
1857 static void
1858 pcn_stop(struct ifnet *ifp, int disable)
1859 {
1860 	struct pcn_softc *sc = ifp->if_softc;
1861 	struct pcn_txsoft *txs;
1862 	int i;
1863 
1864 	if (sc->sc_flags & PCN_F_HAS_MII) {
1865 		/* Stop the one second clock. */
1866 		callout_stop(&sc->sc_tick_ch);
1867 
1868 		/* Down the MII. */
1869 		mii_down(&sc->sc_mii);
1870 	}
1871 
1872 	/* Stop the chip. */
1873 	pcn_csr_write(sc, LE_CSR0, LE_C0_STOP);
1874 
1875 	/* Release any queued transmit buffers. */
1876 	for (i = 0; i < PCN_TXQUEUELEN; i++) {
1877 		txs = &sc->sc_txsoft[i];
1878 		if (txs->txs_mbuf != NULL) {
1879 			bus_dmamap_unload(sc->sc_dmat, txs->txs_dmamap);
1880 			m_freem(txs->txs_mbuf);
1881 			txs->txs_mbuf = NULL;
1882 		}
1883 	}
1884 
1885 	/* Mark the interface as down and cancel the watchdog timer. */
1886 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
1887 	ifp->if_timer = 0;
1888 
1889 	if (disable)
1890 		pcn_rxdrain(sc);
1891 }
1892 
1893 /*
1894  * pcn_add_rxbuf:
1895  *
1896  *	Add a receive buffer to the indicated descriptor.
1897  */
1898 static int
1899 pcn_add_rxbuf(struct pcn_softc *sc, int idx)
1900 {
1901 	struct pcn_rxsoft *rxs = &sc->sc_rxsoft[idx];
1902 	struct mbuf *m;
1903 	int error;
1904 
1905 	MGETHDR(m, M_DONTWAIT, MT_DATA);
1906 	if (m == NULL)
1907 		return (ENOBUFS);
1908 
1909 	MCLGET(m, M_DONTWAIT);
1910 	if ((m->m_flags & M_EXT) == 0) {
1911 		m_freem(m);
1912 		return (ENOBUFS);
1913 	}
1914 
1915 	if (rxs->rxs_mbuf != NULL)
1916 		bus_dmamap_unload(sc->sc_dmat, rxs->rxs_dmamap);
1917 
1918 	rxs->rxs_mbuf = m;
1919 
1920 	error = bus_dmamap_load(sc->sc_dmat, rxs->rxs_dmamap,
1921 	    m->m_ext.ext_buf, m->m_ext.ext_size, NULL,
1922 	    BUS_DMA_READ|BUS_DMA_NOWAIT);
1923 	if (error) {
1924 		printf("%s: can't load rx DMA map %d, error = %d\n",
1925 		    device_xname(sc->sc_dev), idx, error);
1926 		panic("pcn_add_rxbuf");
1927 	}
1928 
1929 	bus_dmamap_sync(sc->sc_dmat, rxs->rxs_dmamap, 0,
1930 	    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_PREREAD);
1931 
1932 	PCN_INIT_RXDESC(sc, idx);
1933 
1934 	return (0);
1935 }
1936 
1937 /*
1938  * pcn_set_filter:
1939  *
1940  *	Set up the receive filter.
1941  */
1942 static void
1943 pcn_set_filter(struct pcn_softc *sc)
1944 {
1945 	struct ethercom *ec = &sc->sc_ethercom;
1946 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
1947 	struct ether_multi *enm;
1948 	struct ether_multistep step;
1949 	uint32_t crc;
1950 
1951 	/*
1952 	 * Set up the multicast address filter by passing all multicast
1953 	 * addresses through a CRC generator, and then using the high
1954 	 * order 6 bits as an index into the 64-bit logical address
1955 	 * filter.  The high order bits select the word, while the rest
1956 	 * of the bits select the bit within the word.
1957 	 */
1958 
1959 	if (ifp->if_flags & IFF_PROMISC)
1960 		goto allmulti;
1961 
1962 	sc->sc_initblock.init_ladrf[0] =
1963 	    sc->sc_initblock.init_ladrf[1] =
1964 	    sc->sc_initblock.init_ladrf[2] =
1965 	    sc->sc_initblock.init_ladrf[3] = 0;
1966 
1967 	ETHER_FIRST_MULTI(step, ec, enm);
1968 	while (enm != NULL) {
1969 		if (memcmp(enm->enm_addrlo, enm->enm_addrhi, ETHER_ADDR_LEN)) {
1970 			/*
1971 			 * We must listen to a range of multicast addresses.
1972 			 * For now, just accept all multicasts, rather than
1973 			 * trying to set only those filter bits needed to match
1974 			 * the range.  (At this time, the only use of address
1975 			 * ranges is for IP multicast routing, for which the
1976 			 * range is big enough to require all bits set.)
1977 			 */
1978 			goto allmulti;
1979 		}
1980 
1981 		crc = ether_crc32_le(enm->enm_addrlo, ETHER_ADDR_LEN);
1982 
1983 		/* Just want the 6 most significant bits. */
1984 		crc >>= 26;
1985 
1986 		/* Set the corresponding bit in the filter. */
1987 		sc->sc_initblock.init_ladrf[crc >> 4] |=
1988 		    htole16(1 << (crc & 0xf));
1989 
1990 		ETHER_NEXT_MULTI(step, enm);
1991 	}
1992 
1993 	ifp->if_flags &= ~IFF_ALLMULTI;
1994 	return;
1995 
1996  allmulti:
1997 	ifp->if_flags |= IFF_ALLMULTI;
1998 	sc->sc_initblock.init_ladrf[0] =
1999 	    sc->sc_initblock.init_ladrf[1] =
2000 	    sc->sc_initblock.init_ladrf[2] =
2001 	    sc->sc_initblock.init_ladrf[3] = 0xffff;
2002 }
2003 
2004 /*
2005  * pcn_79c970_mediainit:
2006  *
2007  *	Initialize media for the Am79c970.
2008  */
2009 static void
2010 pcn_79c970_mediainit(struct pcn_softc *sc)
2011 {
2012 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
2013 	const char *sep = "";
2014 
2015 	sc->sc_mii.mii_ifp = ifp;
2016 
2017 	ifmedia_init(&sc->sc_mii.mii_media, IFM_IMASK, pcn_79c970_mediachange,
2018 	    pcn_79c970_mediastatus);
2019 
2020 #define	ADD(str, m, d)							\
2021 do {									\
2022 	aprint_normal("%s%s", sep, str);					\
2023 	ifmedia_add(&sc->sc_mii.mii_media, IFM_ETHER|(m), (d), NULL);	\
2024 	sep = ", ";							\
2025 } while (/*CONSTCOND*/0)
2026 
2027 	aprint_normal("%s: ", device_xname(sc->sc_dev));
2028 	ADD("10base5", IFM_10_5, PORTSEL_AUI);
2029 	if (sc->sc_variant->pcv_chipid == PARTID_Am79c970A)
2030 		ADD("10base5-FDX", IFM_10_5|IFM_FDX, PORTSEL_AUI);
2031 	ADD("10baseT", IFM_10_T, PORTSEL_10T);
2032 	if (sc->sc_variant->pcv_chipid == PARTID_Am79c970A)
2033 		ADD("10baseT-FDX", IFM_10_T|IFM_FDX, PORTSEL_10T);
2034 	ADD("auto", IFM_AUTO, 0);
2035 	if (sc->sc_variant->pcv_chipid == PARTID_Am79c970A)
2036 		ADD("auto-FDX", IFM_AUTO|IFM_FDX, 0);
2037 	aprint_normal("\n");
2038 
2039 	ifmedia_set(&sc->sc_mii.mii_media, IFM_ETHER|IFM_AUTO);
2040 }
2041 
2042 /*
2043  * pcn_79c970_mediastatus:	[ifmedia interface function]
2044  *
2045  *	Get the current interface media status (Am79c970 version).
2046  */
2047 static void
2048 pcn_79c970_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
2049 {
2050 	struct pcn_softc *sc = ifp->if_softc;
2051 
2052 	/*
2053 	 * The currently selected media is always the active media.
2054 	 * Note: We have no way to determine what media the AUTO
2055 	 * process picked.
2056 	 */
2057 	ifmr->ifm_active = sc->sc_mii.mii_media.ifm_media;
2058 }
2059 
2060 /*
2061  * pcn_79c970_mediachange:	[ifmedia interface function]
2062  *
2063  *	Set hardware to newly-selected media (Am79c970 version).
2064  */
2065 static int
2066 pcn_79c970_mediachange(struct ifnet *ifp)
2067 {
2068 	struct pcn_softc *sc = ifp->if_softc;
2069 	uint32_t reg;
2070 
2071 	if (IFM_SUBTYPE(sc->sc_mii.mii_media.ifm_media) == IFM_AUTO) {
2072 		/*
2073 		 * CSR15:PORTSEL doesn't matter.  Just set BCR2:ASEL.
2074 		 */
2075 		reg = pcn_bcr_read(sc, LE_BCR2);
2076 		reg |= LE_B2_ASEL;
2077 		pcn_bcr_write(sc, LE_BCR2, reg);
2078 	} else {
2079 		/*
2080 		 * Clear BCR2:ASEL and set the new CSR15:PORTSEL value.
2081 		 */
2082 		reg = pcn_bcr_read(sc, LE_BCR2);
2083 		reg &= ~LE_B2_ASEL;
2084 		pcn_bcr_write(sc, LE_BCR2, reg);
2085 
2086 		reg = pcn_csr_read(sc, LE_CSR15);
2087 		reg = (reg & ~LE_C15_PORTSEL(PORTSEL_MASK)) |
2088 		    LE_C15_PORTSEL(sc->sc_mii.mii_media.ifm_cur->ifm_data);
2089 		pcn_csr_write(sc, LE_CSR15, reg);
2090 	}
2091 
2092 	if ((sc->sc_mii.mii_media.ifm_media & IFM_FDX) != 0) {
2093 		reg = LE_B9_FDEN;
2094 		if (IFM_SUBTYPE(sc->sc_mii.mii_media.ifm_media) == IFM_10_5)
2095 			reg |= LE_B9_AUIFD;
2096 		pcn_bcr_write(sc, LE_BCR9, reg);
2097 	} else
2098 		pcn_bcr_write(sc, LE_BCR9, 0);
2099 
2100 	return (0);
2101 }
2102 
2103 /*
2104  * pcn_79c971_mediainit:
2105  *
2106  *	Initialize media for the Am79c971.
2107  */
2108 static void
2109 pcn_79c971_mediainit(struct pcn_softc *sc)
2110 {
2111 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
2112 
2113 	/* We have MII. */
2114 	sc->sc_flags |= PCN_F_HAS_MII;
2115 
2116 	/*
2117 	 * The built-in 10BASE-T interface is mapped to the MII
2118 	 * on the PCNet-FAST.  Unfortunately, there's no EEPROM
2119 	 * word that tells us which PHY to use.
2120 	 * This driver used to ignore all but the first PHY to
2121 	 * answer, but this code was removed to support multiple
2122 	 * external PHYs. As the default instance will be the first
2123 	 * one to answer, no harm is done by letting the possibly
2124 	 * non-connected internal PHY show up.
2125 	 */
2126 
2127 	/* Initialize our media structures and probe the MII. */
2128 	sc->sc_mii.mii_ifp = ifp;
2129 	sc->sc_mii.mii_readreg = pcn_mii_readreg;
2130 	sc->sc_mii.mii_writereg = pcn_mii_writereg;
2131 	sc->sc_mii.mii_statchg = pcn_mii_statchg;
2132 
2133 	sc->sc_ethercom.ec_mii = &sc->sc_mii;
2134 	ifmedia_init(&sc->sc_mii.mii_media, 0, ether_mediachange,
2135 	    ether_mediastatus);
2136 
2137 	mii_attach(sc->sc_dev, &sc->sc_mii, 0xffffffff, MII_PHY_ANY,
2138 	    MII_OFFSET_ANY, 0);
2139 	if (LIST_FIRST(&sc->sc_mii.mii_phys) == NULL) {
2140 		ifmedia_add(&sc->sc_mii.mii_media, IFM_ETHER|IFM_NONE, 0, NULL);
2141 		ifmedia_set(&sc->sc_mii.mii_media, IFM_ETHER|IFM_NONE);
2142 	} else
2143 		ifmedia_set(&sc->sc_mii.mii_media, IFM_ETHER|IFM_AUTO);
2144 }
2145 
2146 /*
2147  * pcn_mii_readreg:	[mii interface function]
2148  *
2149  *	Read a PHY register on the MII.
2150  */
2151 static int
2152 pcn_mii_readreg(device_t self, int phy, int reg)
2153 {
2154 	struct pcn_softc *sc = device_private(self);
2155 	uint32_t rv;
2156 
2157 	pcn_bcr_write(sc, LE_BCR33, reg | (phy << PHYAD_SHIFT));
2158 	rv = pcn_bcr_read(sc, LE_BCR34) & LE_B34_MIIMD;
2159 	if (rv == 0xffff)
2160 		return (0);
2161 
2162 	return (rv);
2163 }
2164 
2165 /*
2166  * pcn_mii_writereg:	[mii interface function]
2167  *
2168  *	Write a PHY register on the MII.
2169  */
2170 static void
2171 pcn_mii_writereg(device_t self, int phy, int reg, int val)
2172 {
2173 	struct pcn_softc *sc = device_private(self);
2174 
2175 	pcn_bcr_write(sc, LE_BCR33, reg | (phy << PHYAD_SHIFT));
2176 	pcn_bcr_write(sc, LE_BCR34, val);
2177 }
2178 
2179 /*
2180  * pcn_mii_statchg:	[mii interface function]
2181  *
2182  *	Callback from MII layer when media changes.
2183  */
2184 static void
2185 pcn_mii_statchg(struct ifnet *ifp)
2186 {
2187 	struct pcn_softc *sc = ifp->if_softc;
2188 
2189 	if ((sc->sc_mii.mii_media_active & IFM_FDX) != 0)
2190 		pcn_bcr_write(sc, LE_BCR9, LE_B9_FDEN);
2191 	else
2192 		pcn_bcr_write(sc, LE_BCR9, 0);
2193 }
2194