xref: /netbsd-src/sys/dev/pci/if_pcn.c (revision 6cf6fe02a981b55727c49c3d37b0d8191a98c0ee)
1 /*	$NetBSD: if_pcn.c,v 1.58 2014/08/10 16:44:36 tls 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 1.58 2014/08/10 16:44:36 tls 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/rnd.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 	ether_ifattach(ifp, enaddr);
816 	rnd_attach_source(&sc->rnd_source, device_xname(self),
817 	    RND_TYPE_NET, RND_FLAG_DEFAULT);
818 
819 #ifdef PCN_EVENT_COUNTERS
820 	/* Attach event counters. */
821 	evcnt_attach_dynamic(&sc->sc_ev_txsstall, EVCNT_TYPE_MISC,
822 	    NULL, device_xname(self), "txsstall");
823 	evcnt_attach_dynamic(&sc->sc_ev_txdstall, EVCNT_TYPE_MISC,
824 	    NULL, device_xname(self), "txdstall");
825 	evcnt_attach_dynamic(&sc->sc_ev_txintr, EVCNT_TYPE_INTR,
826 	    NULL, device_xname(self), "txintr");
827 	evcnt_attach_dynamic(&sc->sc_ev_rxintr, EVCNT_TYPE_INTR,
828 	    NULL, device_xname(self), "rxintr");
829 	evcnt_attach_dynamic(&sc->sc_ev_babl, EVCNT_TYPE_MISC,
830 	    NULL, device_xname(self), "babl");
831 	evcnt_attach_dynamic(&sc->sc_ev_miss, EVCNT_TYPE_MISC,
832 	    NULL, device_xname(self), "miss");
833 	evcnt_attach_dynamic(&sc->sc_ev_merr, EVCNT_TYPE_MISC,
834 	    NULL, device_xname(self), "merr");
835 
836 	evcnt_attach_dynamic(&sc->sc_ev_txseg1, EVCNT_TYPE_MISC,
837 	    NULL, device_xname(self), "txseg1");
838 	evcnt_attach_dynamic(&sc->sc_ev_txseg2, EVCNT_TYPE_MISC,
839 	    NULL, device_xname(self), "txseg2");
840 	evcnt_attach_dynamic(&sc->sc_ev_txseg3, EVCNT_TYPE_MISC,
841 	    NULL, device_xname(self), "txseg3");
842 	evcnt_attach_dynamic(&sc->sc_ev_txseg4, EVCNT_TYPE_MISC,
843 	    NULL, device_xname(self), "txseg4");
844 	evcnt_attach_dynamic(&sc->sc_ev_txseg5, EVCNT_TYPE_MISC,
845 	    NULL, device_xname(self), "txseg5");
846 	evcnt_attach_dynamic(&sc->sc_ev_txsegmore, EVCNT_TYPE_MISC,
847 	    NULL, device_xname(self), "txsegmore");
848 	evcnt_attach_dynamic(&sc->sc_ev_txcopy, EVCNT_TYPE_MISC,
849 	    NULL, device_xname(self), "txcopy");
850 #endif /* PCN_EVENT_COUNTERS */
851 
852 	/*
853 	 * Establish power handler with shutdown hook, to make sure
854 	 * the interface is shutdown during reboot.
855 	 */
856 	if (pmf_device_register1(self, NULL, NULL, pcn_shutdown))
857 		pmf_class_network_register(self, ifp);
858 	else
859 		aprint_error_dev(self, "couldn't establish power handler\n");
860 
861 	return;
862 
863 	/*
864 	 * Free any resources we've allocated during the failed attach
865 	 * attempt.  Do this in reverse order and fall through.
866 	 */
867  fail_5:
868 	for (i = 0; i < PCN_NRXDESC; i++) {
869 		if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
870 			bus_dmamap_destroy(sc->sc_dmat,
871 			    sc->sc_rxsoft[i].rxs_dmamap);
872 	}
873  fail_4:
874 	for (i = 0; i < PCN_TXQUEUELEN; i++) {
875 		if (sc->sc_txsoft[i].txs_dmamap != NULL)
876 			bus_dmamap_destroy(sc->sc_dmat,
877 			    sc->sc_txsoft[i].txs_dmamap);
878 	}
879 	bus_dmamap_unload(sc->sc_dmat, sc->sc_cddmamap);
880  fail_3:
881 	bus_dmamap_destroy(sc->sc_dmat, sc->sc_cddmamap);
882  fail_2:
883 	bus_dmamem_unmap(sc->sc_dmat, (void *)sc->sc_control_data,
884 	    sizeof(struct pcn_control_data));
885  fail_1:
886 	bus_dmamem_free(sc->sc_dmat, &seg, rseg);
887  fail_0:
888 	return;
889 }
890 
891 /*
892  * pcn_shutdown:
893  *
894  *	Make sure the interface is stopped at reboot time.
895  */
896 static bool
897 pcn_shutdown(device_t self, int howto)
898 {
899 	struct pcn_softc *sc = device_private(self);
900 
901 	pcn_stop(&sc->sc_ethercom.ec_if, 1);
902 	/* explicitly reset the chip for some onboard one with lazy firmware */
903 	pcn_reset(sc);
904 
905 	return true;
906 }
907 
908 /*
909  * pcn_start:		[ifnet interface function]
910  *
911  *	Start packet transmission on the interface.
912  */
913 static void
914 pcn_start(struct ifnet *ifp)
915 {
916 	struct pcn_softc *sc = ifp->if_softc;
917 	struct mbuf *m0, *m;
918 	struct pcn_txsoft *txs;
919 	bus_dmamap_t dmamap;
920 	int error, nexttx, lasttx = -1, ofree, seg;
921 
922 	if ((ifp->if_flags & (IFF_RUNNING|IFF_OACTIVE)) != IFF_RUNNING)
923 		return;
924 
925 	/*
926 	 * Remember the previous number of free descriptors and
927 	 * the first descriptor we'll use.
928 	 */
929 	ofree = sc->sc_txfree;
930 
931 	/*
932 	 * Loop through the send queue, setting up transmit descriptors
933 	 * until we drain the queue, or use up all available transmit
934 	 * descriptors.
935 	 */
936 	for (;;) {
937 		/* Grab a packet off the queue. */
938 		IFQ_POLL(&ifp->if_snd, m0);
939 		if (m0 == NULL)
940 			break;
941 		m = NULL;
942 
943 		/* Get a work queue entry. */
944 		if (sc->sc_txsfree == 0) {
945 			PCN_EVCNT_INCR(&sc->sc_ev_txsstall);
946 			break;
947 		}
948 
949 		txs = &sc->sc_txsoft[sc->sc_txsnext];
950 		dmamap = txs->txs_dmamap;
951 
952 		/*
953 		 * Load the DMA map.  If this fails, the packet either
954 		 * didn't fit in the alloted number of segments, or we
955 		 * were short on resources.  In this case, we'll copy
956 		 * and try again.
957 		 */
958 		if (bus_dmamap_load_mbuf(sc->sc_dmat, dmamap, m0,
959 		    BUS_DMA_WRITE|BUS_DMA_NOWAIT) != 0) {
960 			PCN_EVCNT_INCR(&sc->sc_ev_txcopy);
961 			MGETHDR(m, M_DONTWAIT, MT_DATA);
962 			if (m == NULL) {
963 				printf("%s: unable to allocate Tx mbuf\n",
964 				    device_xname(sc->sc_dev));
965 				break;
966 			}
967 			if (m0->m_pkthdr.len > MHLEN) {
968 				MCLGET(m, M_DONTWAIT);
969 				if ((m->m_flags & M_EXT) == 0) {
970 					printf("%s: unable to allocate Tx "
971 					    "cluster\n",
972 					    device_xname(sc->sc_dev));
973 					m_freem(m);
974 					break;
975 				}
976 			}
977 			m_copydata(m0, 0, m0->m_pkthdr.len, mtod(m, void *));
978 			m->m_pkthdr.len = m->m_len = m0->m_pkthdr.len;
979 			error = bus_dmamap_load_mbuf(sc->sc_dmat, dmamap,
980 			    m, BUS_DMA_WRITE|BUS_DMA_NOWAIT);
981 			if (error) {
982 				printf("%s: unable to load Tx buffer, "
983 				    "error = %d\n", device_xname(sc->sc_dev),
984 				    error);
985 				break;
986 			}
987 		}
988 
989 		/*
990 		 * Ensure we have enough descriptors free to describe
991 		 * the packet.  Note, we always reserve one descriptor
992 		 * at the end of the ring as a termination point, to
993 		 * prevent wrap-around.
994 		 */
995 		if (dmamap->dm_nsegs > (sc->sc_txfree - 1)) {
996 			/*
997 			 * Not enough free descriptors to transmit this
998 			 * packet.  We haven't committed anything yet,
999 			 * so just unload the DMA map, put the packet
1000 			 * back on the queue, and punt.  Notify the upper
1001 			 * layer that there are not more slots left.
1002 			 *
1003 			 * XXX We could allocate an mbuf and copy, but
1004 			 * XXX is it worth it?
1005 			 */
1006 			ifp->if_flags |= IFF_OACTIVE;
1007 			bus_dmamap_unload(sc->sc_dmat, dmamap);
1008 			if (m != NULL)
1009 				m_freem(m);
1010 			PCN_EVCNT_INCR(&sc->sc_ev_txdstall);
1011 			break;
1012 		}
1013 
1014 		IFQ_DEQUEUE(&ifp->if_snd, m0);
1015 		if (m != NULL) {
1016 			m_freem(m0);
1017 			m0 = m;
1018 		}
1019 
1020 		/*
1021 		 * WE ARE NOW COMMITTED TO TRANSMITTING THE PACKET.
1022 		 */
1023 
1024 		/* Sync the DMA map. */
1025 		bus_dmamap_sync(sc->sc_dmat, dmamap, 0, dmamap->dm_mapsize,
1026 		    BUS_DMASYNC_PREWRITE);
1027 
1028 #ifdef PCN_EVENT_COUNTERS
1029 		switch (dmamap->dm_nsegs) {
1030 		case 1:
1031 			PCN_EVCNT_INCR(&sc->sc_ev_txseg1);
1032 			break;
1033 		case 2:
1034 			PCN_EVCNT_INCR(&sc->sc_ev_txseg2);
1035 			break;
1036 		case 3:
1037 			PCN_EVCNT_INCR(&sc->sc_ev_txseg3);
1038 			break;
1039 		case 4:
1040 			PCN_EVCNT_INCR(&sc->sc_ev_txseg4);
1041 			break;
1042 		case 5:
1043 			PCN_EVCNT_INCR(&sc->sc_ev_txseg5);
1044 			break;
1045 		default:
1046 			PCN_EVCNT_INCR(&sc->sc_ev_txsegmore);
1047 			break;
1048 		}
1049 #endif /* PCN_EVENT_COUNTERS */
1050 
1051 		/*
1052 		 * Initialize the transmit descriptors.
1053 		 */
1054 		if (sc->sc_swstyle == LE_B20_SSTYLE_PCNETPCI3) {
1055 			for (nexttx = sc->sc_txnext, seg = 0;
1056 			     seg < dmamap->dm_nsegs;
1057 			     seg++, nexttx = PCN_NEXTTX(nexttx)) {
1058 				/*
1059 				 * If this is the first descriptor we're
1060 				 * enqueueing, don't set the OWN bit just
1061 				 * yet.  That could cause a race condition.
1062 				 * We'll do it below.
1063 				 */
1064 				sc->sc_txdescs[nexttx].tmd0 = 0;
1065 				sc->sc_txdescs[nexttx].tmd2 =
1066 				    htole32(dmamap->dm_segs[seg].ds_addr);
1067 				sc->sc_txdescs[nexttx].tmd1 =
1068 				    htole32(LE_T1_ONES |
1069 				    (nexttx == sc->sc_txnext ? 0 : LE_T1_OWN) |
1070 				    (LE_BCNT(dmamap->dm_segs[seg].ds_len) &
1071 				     LE_T1_BCNT_MASK));
1072 				lasttx = nexttx;
1073 			}
1074 		} else {
1075 			for (nexttx = sc->sc_txnext, seg = 0;
1076 			     seg < dmamap->dm_nsegs;
1077 			     seg++, nexttx = PCN_NEXTTX(nexttx)) {
1078 				/*
1079 				 * If this is the first descriptor we're
1080 				 * enqueueing, don't set the OWN bit just
1081 				 * yet.  That could cause a race condition.
1082 				 * We'll do it below.
1083 				 */
1084 				sc->sc_txdescs[nexttx].tmd0 =
1085 				    htole32(dmamap->dm_segs[seg].ds_addr);
1086 				sc->sc_txdescs[nexttx].tmd2 = 0;
1087 				sc->sc_txdescs[nexttx].tmd1 =
1088 				    htole32(LE_T1_ONES |
1089 				    (nexttx == sc->sc_txnext ? 0 : LE_T1_OWN) |
1090 				    (LE_BCNT(dmamap->dm_segs[seg].ds_len) &
1091 				     LE_T1_BCNT_MASK));
1092 				lasttx = nexttx;
1093 			}
1094 		}
1095 
1096 		KASSERT(lasttx != -1);
1097 		/* Interrupt on the packet, if appropriate. */
1098 		if ((sc->sc_txsnext & PCN_TXINTR_MASK) == 0)
1099 			sc->sc_txdescs[lasttx].tmd1 |= htole32(LE_T1_LTINT);
1100 
1101 		/* Set `start of packet' and `end of packet' appropriately. */
1102 		sc->sc_txdescs[lasttx].tmd1 |= htole32(LE_T1_ENP);
1103 		sc->sc_txdescs[sc->sc_txnext].tmd1 |=
1104 		    htole32(LE_T1_OWN|LE_T1_STP);
1105 
1106 		/* Sync the descriptors we're using. */
1107 		PCN_CDTXSYNC(sc, sc->sc_txnext, dmamap->dm_nsegs,
1108 		    BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
1109 
1110 		/* Kick the transmitter. */
1111 		pcn_csr_write(sc, LE_CSR0, LE_C0_INEA|LE_C0_TDMD);
1112 
1113 		/*
1114 		 * Store a pointer to the packet so we can free it later,
1115 		 * and remember what txdirty will be once the packet is
1116 		 * done.
1117 		 */
1118 		txs->txs_mbuf = m0;
1119 		txs->txs_firstdesc = sc->sc_txnext;
1120 		txs->txs_lastdesc = lasttx;
1121 
1122 		/* Advance the tx pointer. */
1123 		sc->sc_txfree -= dmamap->dm_nsegs;
1124 		sc->sc_txnext = nexttx;
1125 
1126 		sc->sc_txsfree--;
1127 		sc->sc_txsnext = PCN_NEXTTXS(sc->sc_txsnext);
1128 
1129 		/* Pass the packet to any BPF listeners. */
1130 		bpf_mtap(ifp, m0);
1131 	}
1132 
1133 	if (sc->sc_txsfree == 0 || sc->sc_txfree == 0) {
1134 		/* No more slots left; notify upper layer. */
1135 		ifp->if_flags |= IFF_OACTIVE;
1136 	}
1137 
1138 	if (sc->sc_txfree != ofree) {
1139 		/* Set a watchdog timer in case the chip flakes out. */
1140 		ifp->if_timer = 5;
1141 	}
1142 }
1143 
1144 /*
1145  * pcn_watchdog:	[ifnet interface function]
1146  *
1147  *	Watchdog timer handler.
1148  */
1149 static void
1150 pcn_watchdog(struct ifnet *ifp)
1151 {
1152 	struct pcn_softc *sc = ifp->if_softc;
1153 
1154 	/*
1155 	 * Since we're not interrupting every packet, sweep
1156 	 * up before we report an error.
1157 	 */
1158 	pcn_txintr(sc);
1159 
1160 	if (sc->sc_txfree != PCN_NTXDESC) {
1161 		printf("%s: device timeout (txfree %d txsfree %d)\n",
1162 		    device_xname(sc->sc_dev), sc->sc_txfree, sc->sc_txsfree);
1163 		ifp->if_oerrors++;
1164 
1165 		/* Reset the interface. */
1166 		(void) pcn_init(ifp);
1167 	}
1168 
1169 	/* Try to get more packets going. */
1170 	pcn_start(ifp);
1171 }
1172 
1173 /*
1174  * pcn_ioctl:		[ifnet interface function]
1175  *
1176  *	Handle control requests from the operator.
1177  */
1178 static int
1179 pcn_ioctl(struct ifnet *ifp, u_long cmd, void *data)
1180 {
1181 	struct pcn_softc *sc = ifp->if_softc;
1182 	struct ifreq *ifr = (struct ifreq *) data;
1183 	int s, error;
1184 
1185 	s = splnet();
1186 
1187 	switch (cmd) {
1188 	case SIOCSIFMEDIA:
1189 	case SIOCGIFMEDIA:
1190 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_mii.mii_media, cmd);
1191 		break;
1192 
1193 	default:
1194 		error = ether_ioctl(ifp, cmd, data);
1195 		if (error == ENETRESET) {
1196 			/*
1197 			 * Multicast list has changed; set the hardware filter
1198 			 * accordingly.
1199 			 */
1200 			if (ifp->if_flags & IFF_RUNNING)
1201 				error = pcn_init(ifp);
1202 			else
1203 				error = 0;
1204 		}
1205 		break;
1206 	}
1207 
1208 	/* Try to get more packets going. */
1209 	pcn_start(ifp);
1210 
1211 	splx(s);
1212 	return (error);
1213 }
1214 
1215 /*
1216  * pcn_intr:
1217  *
1218  *	Interrupt service routine.
1219  */
1220 static int
1221 pcn_intr(void *arg)
1222 {
1223 	struct pcn_softc *sc = arg;
1224 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
1225 	uint32_t csr0;
1226 	int wantinit, handled = 0;
1227 
1228 	for (wantinit = 0; wantinit == 0;) {
1229 		csr0 = pcn_csr_read(sc, LE_CSR0);
1230 		if ((csr0 & LE_C0_INTR) == 0)
1231 			break;
1232 
1233 		rnd_add_uint32(&sc->rnd_source, csr0);
1234 
1235 		/* ACK the bits and re-enable interrupts. */
1236 		pcn_csr_write(sc, LE_CSR0, csr0 &
1237 		    (LE_C0_INEA|LE_C0_BABL|LE_C0_MISS|LE_C0_MERR|LE_C0_RINT|
1238 		     LE_C0_TINT|LE_C0_IDON));
1239 
1240 		handled = 1;
1241 
1242 		if (csr0 & LE_C0_RINT) {
1243 			PCN_EVCNT_INCR(&sc->sc_ev_rxintr);
1244 			wantinit = pcn_rxintr(sc);
1245 		}
1246 
1247 		if (csr0 & LE_C0_TINT) {
1248 			PCN_EVCNT_INCR(&sc->sc_ev_txintr);
1249 			pcn_txintr(sc);
1250 		}
1251 
1252 		if (csr0 & LE_C0_ERR) {
1253 			if (csr0 & LE_C0_BABL) {
1254 				PCN_EVCNT_INCR(&sc->sc_ev_babl);
1255 				ifp->if_oerrors++;
1256 			}
1257 			if (csr0 & LE_C0_MISS) {
1258 				PCN_EVCNT_INCR(&sc->sc_ev_miss);
1259 				ifp->if_ierrors++;
1260 			}
1261 			if (csr0 & LE_C0_MERR) {
1262 				PCN_EVCNT_INCR(&sc->sc_ev_merr);
1263 				printf("%s: memory error\n",
1264 				    device_xname(sc->sc_dev));
1265 				wantinit = 1;
1266 				break;
1267 			}
1268 		}
1269 
1270 		if ((csr0 & LE_C0_RXON) == 0) {
1271 			printf("%s: receiver disabled\n",
1272 			    device_xname(sc->sc_dev));
1273 			ifp->if_ierrors++;
1274 			wantinit = 1;
1275 		}
1276 
1277 		if ((csr0 & LE_C0_TXON) == 0) {
1278 			printf("%s: transmitter disabled\n",
1279 			    device_xname(sc->sc_dev));
1280 			ifp->if_oerrors++;
1281 			wantinit = 1;
1282 		}
1283 	}
1284 
1285 	if (handled) {
1286 		if (wantinit)
1287 			pcn_init(ifp);
1288 
1289 		/* Try to get more packets going. */
1290 		pcn_start(ifp);
1291 	}
1292 
1293 	return (handled);
1294 }
1295 
1296 /*
1297  * pcn_spnd:
1298  *
1299  *	Suspend the chip.
1300  */
1301 static void
1302 pcn_spnd(struct pcn_softc *sc)
1303 {
1304 	int i;
1305 
1306 	pcn_csr_write(sc, LE_CSR5, sc->sc_csr5 | LE_C5_SPND);
1307 
1308 	for (i = 0; i < 10000; i++) {
1309 		if (pcn_csr_read(sc, LE_CSR5) & LE_C5_SPND)
1310 			return;
1311 		delay(5);
1312 	}
1313 
1314 	printf("%s: WARNING: chip failed to enter suspended state\n",
1315 	    device_xname(sc->sc_dev));
1316 }
1317 
1318 /*
1319  * pcn_txintr:
1320  *
1321  *	Helper; handle transmit interrupts.
1322  */
1323 static void
1324 pcn_txintr(struct pcn_softc *sc)
1325 {
1326 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
1327 	struct pcn_txsoft *txs;
1328 	uint32_t tmd1, tmd2, tmd;
1329 	int i, j;
1330 
1331 	ifp->if_flags &= ~IFF_OACTIVE;
1332 
1333 	/*
1334 	 * Go through our Tx list and free mbufs for those
1335 	 * frames which have been transmitted.
1336 	 */
1337 	for (i = sc->sc_txsdirty; sc->sc_txsfree != PCN_TXQUEUELEN;
1338 	     i = PCN_NEXTTXS(i), sc->sc_txsfree++) {
1339 		txs = &sc->sc_txsoft[i];
1340 
1341 		PCN_CDTXSYNC(sc, txs->txs_firstdesc, txs->txs_dmamap->dm_nsegs,
1342 		    BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
1343 
1344 		tmd1 = le32toh(sc->sc_txdescs[txs->txs_lastdesc].tmd1);
1345 		if (tmd1 & LE_T1_OWN)
1346 			break;
1347 
1348 		/*
1349 		 * Slightly annoying -- we have to loop through the
1350 		 * descriptors we've used looking for ERR, since it
1351 		 * can appear on any descriptor in the chain.
1352 		 */
1353 		for (j = txs->txs_firstdesc;; j = PCN_NEXTTX(j)) {
1354 			tmd = le32toh(sc->sc_txdescs[j].tmd1);
1355 			if (tmd & LE_T1_ERR) {
1356 				ifp->if_oerrors++;
1357 				if (sc->sc_swstyle == LE_B20_SSTYLE_PCNETPCI3)
1358 					tmd2 = le32toh(sc->sc_txdescs[j].tmd0);
1359 				else
1360 					tmd2 = le32toh(sc->sc_txdescs[j].tmd2);
1361 				if (tmd2 & LE_T2_UFLO) {
1362 					if (sc->sc_xmtsp < LE_C80_XMTSP_MAX) {
1363 						sc->sc_xmtsp++;
1364 						printf("%s: transmit "
1365 						    "underrun; new threshold: "
1366 						    "%s\n",
1367 						    device_xname(sc->sc_dev),
1368 						    sc->sc_xmtsp_desc[
1369 						    sc->sc_xmtsp]);
1370 						pcn_spnd(sc);
1371 						pcn_csr_write(sc, LE_CSR80,
1372 						    LE_C80_RCVFW(sc->sc_rcvfw) |
1373 						    LE_C80_XMTSP(sc->sc_xmtsp) |
1374 						    LE_C80_XMTFW(sc->sc_xmtfw));
1375 						pcn_csr_write(sc, LE_CSR5,
1376 						    sc->sc_csr5);
1377 					} else {
1378 						printf("%s: transmit "
1379 						    "underrun\n",
1380 						    device_xname(sc->sc_dev));
1381 					}
1382 				} else if (tmd2 & LE_T2_BUFF) {
1383 					printf("%s: transmit buffer error\n",
1384 					    device_xname(sc->sc_dev));
1385 				}
1386 				if (tmd2 & LE_T2_LCOL)
1387 					ifp->if_collisions++;
1388 				if (tmd2 & LE_T2_RTRY)
1389 					ifp->if_collisions += 16;
1390 				goto next_packet;
1391 			}
1392 			if (j == txs->txs_lastdesc)
1393 				break;
1394 		}
1395 		if (tmd1 & LE_T1_ONE)
1396 			ifp->if_collisions++;
1397 		else if (tmd & LE_T1_MORE) {
1398 			/* Real number is unknown. */
1399 			ifp->if_collisions += 2;
1400 		}
1401 		ifp->if_opackets++;
1402  next_packet:
1403 		sc->sc_txfree += txs->txs_dmamap->dm_nsegs;
1404 		bus_dmamap_sync(sc->sc_dmat, txs->txs_dmamap,
1405 		    0, txs->txs_dmamap->dm_mapsize, BUS_DMASYNC_POSTWRITE);
1406 		bus_dmamap_unload(sc->sc_dmat, txs->txs_dmamap);
1407 		m_freem(txs->txs_mbuf);
1408 		txs->txs_mbuf = NULL;
1409 	}
1410 
1411 	/* Update the dirty transmit buffer pointer. */
1412 	sc->sc_txsdirty = i;
1413 
1414 	/*
1415 	 * If there are no more pending transmissions, cancel the watchdog
1416 	 * timer.
1417 	 */
1418 	if (sc->sc_txsfree == PCN_TXQUEUELEN)
1419 		ifp->if_timer = 0;
1420 }
1421 
1422 /*
1423  * pcn_rxintr:
1424  *
1425  *	Helper; handle receive interrupts.
1426  */
1427 static int
1428 pcn_rxintr(struct pcn_softc *sc)
1429 {
1430 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
1431 	struct pcn_rxsoft *rxs;
1432 	struct mbuf *m;
1433 	uint32_t rmd1;
1434 	int i, len;
1435 
1436 	for (i = sc->sc_rxptr;; i = PCN_NEXTRX(i)) {
1437 		rxs = &sc->sc_rxsoft[i];
1438 
1439 		PCN_CDRXSYNC(sc, i, BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
1440 
1441 		rmd1 = le32toh(sc->sc_rxdescs[i].rmd1);
1442 
1443 		if (rmd1 & LE_R1_OWN)
1444 			break;
1445 
1446 		/*
1447 		 * Check for errors and make sure the packet fit into
1448 		 * a single buffer.  We have structured this block of
1449 		 * code the way it is in order to compress it into
1450 		 * one test in the common case (no error).
1451 		 */
1452 		if (__predict_false((rmd1 & (LE_R1_STP|LE_R1_ENP|LE_R1_ERR)) !=
1453 		    (LE_R1_STP|LE_R1_ENP))) {
1454 			/* Make sure the packet is in a single buffer. */
1455 			if ((rmd1 & (LE_R1_STP|LE_R1_ENP)) !=
1456 			    (LE_R1_STP|LE_R1_ENP)) {
1457 				printf("%s: packet spilled into next buffer\n",
1458 				    device_xname(sc->sc_dev));
1459 				return (1);	/* pcn_intr() will re-init */
1460 			}
1461 
1462 			/*
1463 			 * If the packet had an error, simple recycle the
1464 			 * buffer.
1465 			 */
1466 			if (rmd1 & LE_R1_ERR) {
1467 				ifp->if_ierrors++;
1468 				/*
1469 				 * If we got an overflow error, chances
1470 				 * are there will be a CRC error.  In
1471 				 * this case, just print the overflow
1472 				 * error, and skip the others.
1473 				 */
1474 				if (rmd1 & LE_R1_OFLO)
1475 					printf("%s: overflow error\n",
1476 					    device_xname(sc->sc_dev));
1477 				else {
1478 #define	PRINTIT(x, str)							\
1479 					if (rmd1 & (x))			\
1480 						printf("%s: %s\n",	\
1481 						    device_xname(sc->sc_dev), \
1482 						    str);
1483 					PRINTIT(LE_R1_FRAM, "framing error");
1484 					PRINTIT(LE_R1_CRC, "CRC error");
1485 					PRINTIT(LE_R1_BUFF, "buffer error");
1486 				}
1487 #undef PRINTIT
1488 				PCN_INIT_RXDESC(sc, i);
1489 				continue;
1490 			}
1491 		}
1492 
1493 		bus_dmamap_sync(sc->sc_dmat, rxs->rxs_dmamap, 0,
1494 		    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);
1495 
1496 		/*
1497 		 * No errors; receive the packet.
1498 		 */
1499 		if (sc->sc_swstyle == LE_B20_SSTYLE_PCNETPCI3)
1500 			len = le32toh(sc->sc_rxdescs[i].rmd0) & LE_R1_BCNT_MASK;
1501 		else
1502 			len = le32toh(sc->sc_rxdescs[i].rmd2) & LE_R1_BCNT_MASK;
1503 
1504 		/*
1505 		 * The LANCE family includes the CRC with every packet;
1506 		 * trim it off here.
1507 		 */
1508 		len -= ETHER_CRC_LEN;
1509 
1510 		/*
1511 		 * If the packet is small enough to fit in a
1512 		 * single header mbuf, allocate one and copy
1513 		 * the data into it.  This greatly reduces
1514 		 * memory consumption when we receive lots
1515 		 * of small packets.
1516 		 *
1517 		 * Otherwise, we add a new buffer to the receive
1518 		 * chain.  If this fails, we drop the packet and
1519 		 * recycle the old buffer.
1520 		 */
1521 		if (pcn_copy_small != 0 && len <= (MHLEN - 2)) {
1522 			MGETHDR(m, M_DONTWAIT, MT_DATA);
1523 			if (m == NULL)
1524 				goto dropit;
1525 			m->m_data += 2;
1526 			memcpy(mtod(m, void *),
1527 			    mtod(rxs->rxs_mbuf, void *), len);
1528 			PCN_INIT_RXDESC(sc, i);
1529 			bus_dmamap_sync(sc->sc_dmat, rxs->rxs_dmamap, 0,
1530 			    rxs->rxs_dmamap->dm_mapsize,
1531 			    BUS_DMASYNC_PREREAD);
1532 		} else {
1533 			m = rxs->rxs_mbuf;
1534 			if (pcn_add_rxbuf(sc, i) != 0) {
1535  dropit:
1536 				ifp->if_ierrors++;
1537 				PCN_INIT_RXDESC(sc, i);
1538 				bus_dmamap_sync(sc->sc_dmat,
1539 				    rxs->rxs_dmamap, 0,
1540 				    rxs->rxs_dmamap->dm_mapsize,
1541 				    BUS_DMASYNC_PREREAD);
1542 				continue;
1543 			}
1544 		}
1545 
1546 		m->m_pkthdr.rcvif = ifp;
1547 		m->m_pkthdr.len = m->m_len = len;
1548 
1549 		/* Pass this up to any BPF listeners. */
1550 		bpf_mtap(ifp, m);
1551 
1552 		/* Pass it on. */
1553 		(*ifp->if_input)(ifp, m);
1554 		ifp->if_ipackets++;
1555 	}
1556 
1557 	/* Update the receive pointer. */
1558 	sc->sc_rxptr = i;
1559 	return (0);
1560 }
1561 
1562 /*
1563  * pcn_tick:
1564  *
1565  *	One second timer, used to tick the MII.
1566  */
1567 static void
1568 pcn_tick(void *arg)
1569 {
1570 	struct pcn_softc *sc = arg;
1571 	int s;
1572 
1573 	s = splnet();
1574 	mii_tick(&sc->sc_mii);
1575 	splx(s);
1576 
1577 	callout_reset(&sc->sc_tick_ch, hz, pcn_tick, sc);
1578 }
1579 
1580 /*
1581  * pcn_reset:
1582  *
1583  *	Perform a soft reset on the PCnet-PCI.
1584  */
1585 static void
1586 pcn_reset(struct pcn_softc *sc)
1587 {
1588 
1589 	/*
1590 	 * The PCnet-PCI chip is reset by reading from the
1591 	 * RESET register.  Note that while the NE2100 LANCE
1592 	 * boards require a write after the read, the PCnet-PCI
1593 	 * chips do not require this.
1594 	 *
1595 	 * Since we don't know if we're in 16-bit or 32-bit
1596 	 * mode right now, issue both (it's safe) in the
1597 	 * hopes that one will succeed.
1598 	 */
1599 	(void) bus_space_read_2(sc->sc_st, sc->sc_sh, PCN16_RESET);
1600 	(void) bus_space_read_4(sc->sc_st, sc->sc_sh, PCN32_RESET);
1601 
1602 	/* Wait 1ms for it to finish. */
1603 	delay(1000);
1604 
1605 	/*
1606 	 * Select 32-bit I/O mode by issuing a 32-bit write to the
1607 	 * RDP.  Since the RAP is 0 after a reset, writing a 0
1608 	 * to RDP is safe (since it simply clears CSR0).
1609 	 */
1610 	bus_space_write_4(sc->sc_st, sc->sc_sh, PCN32_RDP, 0);
1611 }
1612 
1613 /*
1614  * pcn_init:		[ifnet interface function]
1615  *
1616  *	Initialize the interface.  Must be called at splnet().
1617  */
1618 static int
1619 pcn_init(struct ifnet *ifp)
1620 {
1621 	struct pcn_softc *sc = ifp->if_softc;
1622 	struct pcn_rxsoft *rxs;
1623 	const uint8_t *enaddr = CLLADDR(ifp->if_sadl);
1624 	int i, error = 0;
1625 	uint32_t reg;
1626 
1627 	/* Cancel any pending I/O. */
1628 	pcn_stop(ifp, 0);
1629 
1630 	/* Reset the chip to a known state. */
1631 	pcn_reset(sc);
1632 
1633 	/*
1634 	 * On the Am79c970, select SSTYLE 2, and SSTYLE 3 on everything
1635 	 * else.
1636 	 *
1637 	 * XXX It'd be really nice to use SSTYLE 2 on all the chips,
1638 	 * because the structure layout is compatible with ILACC,
1639 	 * but the burst mode is only available in SSTYLE 3, and
1640 	 * burst mode should provide some performance enhancement.
1641 	 */
1642 	if (sc->sc_variant->pcv_chipid == PARTID_Am79c970)
1643 		sc->sc_swstyle = LE_B20_SSTYLE_PCNETPCI2;
1644 	else
1645 		sc->sc_swstyle = LE_B20_SSTYLE_PCNETPCI3;
1646 	pcn_bcr_write(sc, LE_BCR20, sc->sc_swstyle);
1647 
1648 	/* Initialize the transmit descriptor ring. */
1649 	memset(sc->sc_txdescs, 0, sizeof(sc->sc_txdescs));
1650 	PCN_CDTXSYNC(sc, 0, PCN_NTXDESC,
1651 	    BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
1652 	sc->sc_txfree = PCN_NTXDESC;
1653 	sc->sc_txnext = 0;
1654 
1655 	/* Initialize the transmit job descriptors. */
1656 	for (i = 0; i < PCN_TXQUEUELEN; i++)
1657 		sc->sc_txsoft[i].txs_mbuf = NULL;
1658 	sc->sc_txsfree = PCN_TXQUEUELEN;
1659 	sc->sc_txsnext = 0;
1660 	sc->sc_txsdirty = 0;
1661 
1662 	/*
1663 	 * Initialize the receive descriptor and receive job
1664 	 * descriptor rings.
1665 	 */
1666 	for (i = 0; i < PCN_NRXDESC; i++) {
1667 		rxs = &sc->sc_rxsoft[i];
1668 		if (rxs->rxs_mbuf == NULL) {
1669 			if ((error = pcn_add_rxbuf(sc, i)) != 0) {
1670 				printf("%s: unable to allocate or map rx "
1671 				    "buffer %d, error = %d\n",
1672 				    device_xname(sc->sc_dev), i, error);
1673 				/*
1674 				 * XXX Should attempt to run with fewer receive
1675 				 * XXX buffers instead of just failing.
1676 				 */
1677 				pcn_rxdrain(sc);
1678 				goto out;
1679 			}
1680 		} else
1681 			PCN_INIT_RXDESC(sc, i);
1682 	}
1683 	sc->sc_rxptr = 0;
1684 
1685 	/* Initialize MODE for the initialization block. */
1686 	sc->sc_mode = 0;
1687 	if (ifp->if_flags & IFF_PROMISC)
1688 		sc->sc_mode |= LE_C15_PROM;
1689 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1690 		sc->sc_mode |= LE_C15_DRCVBC;
1691 
1692 	/*
1693 	 * If we have MII, simply select MII in the MODE register,
1694 	 * and clear ASEL.  Otherwise, let ASEL stand (for now),
1695 	 * and leave PORTSEL alone (it is ignored with ASEL is set).
1696 	 */
1697 	if (sc->sc_flags & PCN_F_HAS_MII) {
1698 		pcn_bcr_write(sc, LE_BCR2,
1699 		    pcn_bcr_read(sc, LE_BCR2) & ~LE_B2_ASEL);
1700 		sc->sc_mode |= LE_C15_PORTSEL(PORTSEL_MII);
1701 
1702 		/*
1703 		 * Disable MII auto-negotiation.  We handle that in
1704 		 * our own MII layer.
1705 		 */
1706 		pcn_bcr_write(sc, LE_BCR32,
1707 		    pcn_bcr_read(sc, LE_BCR32) | LE_B32_DANAS);
1708 	}
1709 
1710 	/*
1711 	 * Set the Tx and Rx descriptor ring addresses in the init
1712 	 * block, the TLEN and RLEN other fields of the init block
1713 	 * MODE register.
1714 	 */
1715 	sc->sc_initblock.init_rdra = htole32(PCN_CDRXADDR(sc, 0));
1716 	sc->sc_initblock.init_tdra = htole32(PCN_CDTXADDR(sc, 0));
1717 	sc->sc_initblock.init_mode = htole32(sc->sc_mode |
1718 	    ((ffs(PCN_NTXDESC) - 1) << 28) |
1719 	    ((ffs(PCN_NRXDESC) - 1) << 20));
1720 
1721 	/* Set the station address in the init block. */
1722 	sc->sc_initblock.init_padr[0] = htole32(enaddr[0] |
1723 	    (enaddr[1] << 8) | (enaddr[2] << 16) | (enaddr[3] << 24));
1724 	sc->sc_initblock.init_padr[1] = htole32(enaddr[4] |
1725 	    (enaddr[5] << 8));
1726 
1727 	/* Set the multicast filter in the init block. */
1728 	pcn_set_filter(sc);
1729 
1730 	/* Initialize CSR3. */
1731 	pcn_csr_write(sc, LE_CSR3, LE_C3_MISSM|LE_C3_IDONM|LE_C3_DXSUFLO);
1732 
1733 	/* Initialize CSR4. */
1734 	pcn_csr_write(sc, LE_CSR4, LE_C4_DMAPLUS|LE_C4_APAD_XMT|
1735 	    LE_C4_MFCOM|LE_C4_RCVCCOM|LE_C4_TXSTRTM);
1736 
1737 	/* Initialize CSR5. */
1738 	sc->sc_csr5 = LE_C5_LTINTEN|LE_C5_SINTE;
1739 	pcn_csr_write(sc, LE_CSR5, sc->sc_csr5);
1740 
1741 	/*
1742 	 * If we have an Am79c971 or greater, initialize CSR7.
1743 	 *
1744 	 * XXX Might be nice to use the MII auto-poll interrupt someday.
1745 	 */
1746 	switch (sc->sc_variant->pcv_chipid) {
1747 	case PARTID_Am79c970:
1748 	case PARTID_Am79c970A:
1749 		/* Not available on these chips. */
1750 		break;
1751 
1752 	default:
1753 		pcn_csr_write(sc, LE_CSR7, LE_C7_FASTSPNDE);
1754 		break;
1755 	}
1756 
1757 	/*
1758 	 * On the Am79c970A and greater, initialize BCR18 to
1759 	 * enable burst mode.
1760 	 *
1761 	 * Also enable the "no underflow" option on the Am79c971 and
1762 	 * higher, which prevents the chip from generating transmit
1763 	 * underflows, yet sill provides decent performance.  Note if
1764 	 * chip is not connected to external SRAM, then we still have
1765 	 * to handle underflow errors (the NOUFLO bit is ignored in
1766 	 * that case).
1767 	 */
1768 	reg = pcn_bcr_read(sc, LE_BCR18);
1769 	switch (sc->sc_variant->pcv_chipid) {
1770 	case PARTID_Am79c970:
1771 		break;
1772 
1773 	case PARTID_Am79c970A:
1774 		reg |= LE_B18_BREADE|LE_B18_BWRITE;
1775 		break;
1776 
1777 	default:
1778 		reg |= LE_B18_BREADE|LE_B18_BWRITE|LE_B18_NOUFLO;
1779 		break;
1780 	}
1781 	pcn_bcr_write(sc, LE_BCR18, reg);
1782 
1783 	/*
1784 	 * Initialize CSR80 (FIFO thresholds for Tx and Rx).
1785 	 */
1786 	pcn_csr_write(sc, LE_CSR80, LE_C80_RCVFW(sc->sc_rcvfw) |
1787 	    LE_C80_XMTSP(sc->sc_xmtsp) | LE_C80_XMTFW(sc->sc_xmtfw));
1788 
1789 	/*
1790 	 * Send the init block to the chip, and wait for it
1791 	 * to be processed.
1792 	 */
1793 	PCN_CDINITSYNC(sc, BUS_DMASYNC_PREWRITE);
1794 	pcn_csr_write(sc, LE_CSR1, PCN_CDINITADDR(sc) & 0xffff);
1795 	pcn_csr_write(sc, LE_CSR2, (PCN_CDINITADDR(sc) >> 16) & 0xffff);
1796 	pcn_csr_write(sc, LE_CSR0, LE_C0_INIT);
1797 	delay(100);
1798 	for (i = 0; i < 10000; i++) {
1799 		if (pcn_csr_read(sc, LE_CSR0) & LE_C0_IDON)
1800 			break;
1801 		delay(10);
1802 	}
1803 	PCN_CDINITSYNC(sc, BUS_DMASYNC_POSTWRITE);
1804 	if (i == 10000) {
1805 		printf("%s: timeout processing init block\n",
1806 		    device_xname(sc->sc_dev));
1807 		error = EIO;
1808 		goto out;
1809 	}
1810 
1811 	/* Set the media. */
1812 	if ((error = mii_ifmedia_change(&sc->sc_mii)) != 0)
1813 		goto out;
1814 
1815 	/* Enable interrupts and external activity (and ACK IDON). */
1816 	pcn_csr_write(sc, LE_CSR0, LE_C0_INEA|LE_C0_STRT|LE_C0_IDON);
1817 
1818 	if (sc->sc_flags & PCN_F_HAS_MII) {
1819 		/* Start the one second MII clock. */
1820 		callout_reset(&sc->sc_tick_ch, hz, pcn_tick, sc);
1821 	}
1822 
1823 	/* ...all done! */
1824 	ifp->if_flags |= IFF_RUNNING;
1825 	ifp->if_flags &= ~IFF_OACTIVE;
1826 
1827  out:
1828 	if (error)
1829 		printf("%s: interface not running\n", device_xname(sc->sc_dev));
1830 	return (error);
1831 }
1832 
1833 /*
1834  * pcn_rxdrain:
1835  *
1836  *	Drain the receive queue.
1837  */
1838 static void
1839 pcn_rxdrain(struct pcn_softc *sc)
1840 {
1841 	struct pcn_rxsoft *rxs;
1842 	int i;
1843 
1844 	for (i = 0; i < PCN_NRXDESC; i++) {
1845 		rxs = &sc->sc_rxsoft[i];
1846 		if (rxs->rxs_mbuf != NULL) {
1847 			bus_dmamap_unload(sc->sc_dmat, rxs->rxs_dmamap);
1848 			m_freem(rxs->rxs_mbuf);
1849 			rxs->rxs_mbuf = NULL;
1850 		}
1851 	}
1852 }
1853 
1854 /*
1855  * pcn_stop:		[ifnet interface function]
1856  *
1857  *	Stop transmission on the interface.
1858  */
1859 static void
1860 pcn_stop(struct ifnet *ifp, int disable)
1861 {
1862 	struct pcn_softc *sc = ifp->if_softc;
1863 	struct pcn_txsoft *txs;
1864 	int i;
1865 
1866 	if (sc->sc_flags & PCN_F_HAS_MII) {
1867 		/* Stop the one second clock. */
1868 		callout_stop(&sc->sc_tick_ch);
1869 
1870 		/* Down the MII. */
1871 		mii_down(&sc->sc_mii);
1872 	}
1873 
1874 	/* Stop the chip. */
1875 	pcn_csr_write(sc, LE_CSR0, LE_C0_STOP);
1876 
1877 	/* Release any queued transmit buffers. */
1878 	for (i = 0; i < PCN_TXQUEUELEN; i++) {
1879 		txs = &sc->sc_txsoft[i];
1880 		if (txs->txs_mbuf != NULL) {
1881 			bus_dmamap_unload(sc->sc_dmat, txs->txs_dmamap);
1882 			m_freem(txs->txs_mbuf);
1883 			txs->txs_mbuf = NULL;
1884 		}
1885 	}
1886 
1887 	/* Mark the interface as down and cancel the watchdog timer. */
1888 	ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
1889 	ifp->if_timer = 0;
1890 
1891 	if (disable)
1892 		pcn_rxdrain(sc);
1893 }
1894 
1895 /*
1896  * pcn_add_rxbuf:
1897  *
1898  *	Add a receive buffer to the indicated descriptor.
1899  */
1900 static int
1901 pcn_add_rxbuf(struct pcn_softc *sc, int idx)
1902 {
1903 	struct pcn_rxsoft *rxs = &sc->sc_rxsoft[idx];
1904 	struct mbuf *m;
1905 	int error;
1906 
1907 	MGETHDR(m, M_DONTWAIT, MT_DATA);
1908 	if (m == NULL)
1909 		return (ENOBUFS);
1910 
1911 	MCLGET(m, M_DONTWAIT);
1912 	if ((m->m_flags & M_EXT) == 0) {
1913 		m_freem(m);
1914 		return (ENOBUFS);
1915 	}
1916 
1917 	if (rxs->rxs_mbuf != NULL)
1918 		bus_dmamap_unload(sc->sc_dmat, rxs->rxs_dmamap);
1919 
1920 	rxs->rxs_mbuf = m;
1921 
1922 	error = bus_dmamap_load(sc->sc_dmat, rxs->rxs_dmamap,
1923 	    m->m_ext.ext_buf, m->m_ext.ext_size, NULL,
1924 	    BUS_DMA_READ|BUS_DMA_NOWAIT);
1925 	if (error) {
1926 		printf("%s: can't load rx DMA map %d, error = %d\n",
1927 		    device_xname(sc->sc_dev), idx, error);
1928 		panic("pcn_add_rxbuf");
1929 	}
1930 
1931 	bus_dmamap_sync(sc->sc_dmat, rxs->rxs_dmamap, 0,
1932 	    rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_PREREAD);
1933 
1934 	PCN_INIT_RXDESC(sc, idx);
1935 
1936 	return (0);
1937 }
1938 
1939 /*
1940  * pcn_set_filter:
1941  *
1942  *	Set up the receive filter.
1943  */
1944 static void
1945 pcn_set_filter(struct pcn_softc *sc)
1946 {
1947 	struct ethercom *ec = &sc->sc_ethercom;
1948 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
1949 	struct ether_multi *enm;
1950 	struct ether_multistep step;
1951 	uint32_t crc;
1952 
1953 	/*
1954 	 * Set up the multicast address filter by passing all multicast
1955 	 * addresses through a CRC generator, and then using the high
1956 	 * order 6 bits as an index into the 64-bit logical address
1957 	 * filter.  The high order bits select the word, while the rest
1958 	 * of the bits select the bit within the word.
1959 	 */
1960 
1961 	if (ifp->if_flags & IFF_PROMISC)
1962 		goto allmulti;
1963 
1964 	sc->sc_initblock.init_ladrf[0] =
1965 	    sc->sc_initblock.init_ladrf[1] =
1966 	    sc->sc_initblock.init_ladrf[2] =
1967 	    sc->sc_initblock.init_ladrf[3] = 0;
1968 
1969 	ETHER_FIRST_MULTI(step, ec, enm);
1970 	while (enm != NULL) {
1971 		if (memcmp(enm->enm_addrlo, enm->enm_addrhi, ETHER_ADDR_LEN)) {
1972 			/*
1973 			 * We must listen to a range of multicast addresses.
1974 			 * For now, just accept all multicasts, rather than
1975 			 * trying to set only those filter bits needed to match
1976 			 * the range.  (At this time, the only use of address
1977 			 * ranges is for IP multicast routing, for which the
1978 			 * range is big enough to require all bits set.)
1979 			 */
1980 			goto allmulti;
1981 		}
1982 
1983 		crc = ether_crc32_le(enm->enm_addrlo, ETHER_ADDR_LEN);
1984 
1985 		/* Just want the 6 most significant bits. */
1986 		crc >>= 26;
1987 
1988 		/* Set the corresponding bit in the filter. */
1989 		sc->sc_initblock.init_ladrf[crc >> 4] |=
1990 		    htole16(1 << (crc & 0xf));
1991 
1992 		ETHER_NEXT_MULTI(step, enm);
1993 	}
1994 
1995 	ifp->if_flags &= ~IFF_ALLMULTI;
1996 	return;
1997 
1998  allmulti:
1999 	ifp->if_flags |= IFF_ALLMULTI;
2000 	sc->sc_initblock.init_ladrf[0] =
2001 	    sc->sc_initblock.init_ladrf[1] =
2002 	    sc->sc_initblock.init_ladrf[2] =
2003 	    sc->sc_initblock.init_ladrf[3] = 0xffff;
2004 }
2005 
2006 /*
2007  * pcn_79c970_mediainit:
2008  *
2009  *	Initialize media for the Am79c970.
2010  */
2011 static void
2012 pcn_79c970_mediainit(struct pcn_softc *sc)
2013 {
2014 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
2015 	const char *sep = "";
2016 
2017 	sc->sc_mii.mii_ifp = ifp;
2018 
2019 	ifmedia_init(&sc->sc_mii.mii_media, IFM_IMASK, pcn_79c970_mediachange,
2020 	    pcn_79c970_mediastatus);
2021 
2022 #define	ADD(str, m, d)							\
2023 do {									\
2024 	aprint_normal("%s%s", sep, str);					\
2025 	ifmedia_add(&sc->sc_mii.mii_media, IFM_ETHER|(m), (d), NULL);	\
2026 	sep = ", ";							\
2027 } while (/*CONSTCOND*/0)
2028 
2029 	aprint_normal("%s: ", device_xname(sc->sc_dev));
2030 	ADD("10base5", IFM_10_5, PORTSEL_AUI);
2031 	if (sc->sc_variant->pcv_chipid == PARTID_Am79c970A)
2032 		ADD("10base5-FDX", IFM_10_5|IFM_FDX, PORTSEL_AUI);
2033 	ADD("10baseT", IFM_10_T, PORTSEL_10T);
2034 	if (sc->sc_variant->pcv_chipid == PARTID_Am79c970A)
2035 		ADD("10baseT-FDX", IFM_10_T|IFM_FDX, PORTSEL_10T);
2036 	ADD("auto", IFM_AUTO, 0);
2037 	if (sc->sc_variant->pcv_chipid == PARTID_Am79c970A)
2038 		ADD("auto-FDX", IFM_AUTO|IFM_FDX, 0);
2039 	aprint_normal("\n");
2040 
2041 	ifmedia_set(&sc->sc_mii.mii_media, IFM_ETHER|IFM_AUTO);
2042 }
2043 
2044 /*
2045  * pcn_79c970_mediastatus:	[ifmedia interface function]
2046  *
2047  *	Get the current interface media status (Am79c970 version).
2048  */
2049 static void
2050 pcn_79c970_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
2051 {
2052 	struct pcn_softc *sc = ifp->if_softc;
2053 
2054 	/*
2055 	 * The currently selected media is always the active media.
2056 	 * Note: We have no way to determine what media the AUTO
2057 	 * process picked.
2058 	 */
2059 	ifmr->ifm_active = sc->sc_mii.mii_media.ifm_media;
2060 }
2061 
2062 /*
2063  * pcn_79c970_mediachange:	[ifmedia interface function]
2064  *
2065  *	Set hardware to newly-selected media (Am79c970 version).
2066  */
2067 static int
2068 pcn_79c970_mediachange(struct ifnet *ifp)
2069 {
2070 	struct pcn_softc *sc = ifp->if_softc;
2071 	uint32_t reg;
2072 
2073 	if (IFM_SUBTYPE(sc->sc_mii.mii_media.ifm_media) == IFM_AUTO) {
2074 		/*
2075 		 * CSR15:PORTSEL doesn't matter.  Just set BCR2:ASEL.
2076 		 */
2077 		reg = pcn_bcr_read(sc, LE_BCR2);
2078 		reg |= LE_B2_ASEL;
2079 		pcn_bcr_write(sc, LE_BCR2, reg);
2080 	} else {
2081 		/*
2082 		 * Clear BCR2:ASEL and set the new CSR15:PORTSEL value.
2083 		 */
2084 		reg = pcn_bcr_read(sc, LE_BCR2);
2085 		reg &= ~LE_B2_ASEL;
2086 		pcn_bcr_write(sc, LE_BCR2, reg);
2087 
2088 		reg = pcn_csr_read(sc, LE_CSR15);
2089 		reg = (reg & ~LE_C15_PORTSEL(PORTSEL_MASK)) |
2090 		    LE_C15_PORTSEL(sc->sc_mii.mii_media.ifm_cur->ifm_data);
2091 		pcn_csr_write(sc, LE_CSR15, reg);
2092 	}
2093 
2094 	if ((sc->sc_mii.mii_media.ifm_media & IFM_FDX) != 0) {
2095 		reg = LE_B9_FDEN;
2096 		if (IFM_SUBTYPE(sc->sc_mii.mii_media.ifm_media) == IFM_10_5)
2097 			reg |= LE_B9_AUIFD;
2098 		pcn_bcr_write(sc, LE_BCR9, reg);
2099 	} else
2100 		pcn_bcr_write(sc, LE_BCR9, 0);
2101 
2102 	return (0);
2103 }
2104 
2105 /*
2106  * pcn_79c971_mediainit:
2107  *
2108  *	Initialize media for the Am79c971.
2109  */
2110 static void
2111 pcn_79c971_mediainit(struct pcn_softc *sc)
2112 {
2113 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
2114 
2115 	/* We have MII. */
2116 	sc->sc_flags |= PCN_F_HAS_MII;
2117 
2118 	/*
2119 	 * The built-in 10BASE-T interface is mapped to the MII
2120 	 * on the PCNet-FAST.  Unfortunately, there's no EEPROM
2121 	 * word that tells us which PHY to use.
2122 	 * This driver used to ignore all but the first PHY to
2123 	 * answer, but this code was removed to support multiple
2124 	 * external PHYs. As the default instance will be the first
2125 	 * one to answer, no harm is done by letting the possibly
2126 	 * non-connected internal PHY show up.
2127 	 */
2128 
2129 	/* Initialize our media structures and probe the MII. */
2130 	sc->sc_mii.mii_ifp = ifp;
2131 	sc->sc_mii.mii_readreg = pcn_mii_readreg;
2132 	sc->sc_mii.mii_writereg = pcn_mii_writereg;
2133 	sc->sc_mii.mii_statchg = pcn_mii_statchg;
2134 
2135 	sc->sc_ethercom.ec_mii = &sc->sc_mii;
2136 	ifmedia_init(&sc->sc_mii.mii_media, 0, ether_mediachange,
2137 	    ether_mediastatus);
2138 
2139 	mii_attach(sc->sc_dev, &sc->sc_mii, 0xffffffff, MII_PHY_ANY,
2140 	    MII_OFFSET_ANY, 0);
2141 	if (LIST_FIRST(&sc->sc_mii.mii_phys) == NULL) {
2142 		ifmedia_add(&sc->sc_mii.mii_media, IFM_ETHER|IFM_NONE, 0, NULL);
2143 		ifmedia_set(&sc->sc_mii.mii_media, IFM_ETHER|IFM_NONE);
2144 	} else
2145 		ifmedia_set(&sc->sc_mii.mii_media, IFM_ETHER|IFM_AUTO);
2146 }
2147 
2148 /*
2149  * pcn_mii_readreg:	[mii interface function]
2150  *
2151  *	Read a PHY register on the MII.
2152  */
2153 static int
2154 pcn_mii_readreg(device_t self, int phy, int reg)
2155 {
2156 	struct pcn_softc *sc = device_private(self);
2157 	uint32_t rv;
2158 
2159 	pcn_bcr_write(sc, LE_BCR33, reg | (phy << PHYAD_SHIFT));
2160 	rv = pcn_bcr_read(sc, LE_BCR34) & LE_B34_MIIMD;
2161 	if (rv == 0xffff)
2162 		return (0);
2163 
2164 	return (rv);
2165 }
2166 
2167 /*
2168  * pcn_mii_writereg:	[mii interface function]
2169  *
2170  *	Write a PHY register on the MII.
2171  */
2172 static void
2173 pcn_mii_writereg(device_t self, int phy, int reg, int val)
2174 {
2175 	struct pcn_softc *sc = device_private(self);
2176 
2177 	pcn_bcr_write(sc, LE_BCR33, reg | (phy << PHYAD_SHIFT));
2178 	pcn_bcr_write(sc, LE_BCR34, val);
2179 }
2180 
2181 /*
2182  * pcn_mii_statchg:	[mii interface function]
2183  *
2184  *	Callback from MII layer when media changes.
2185  */
2186 static void
2187 pcn_mii_statchg(struct ifnet *ifp)
2188 {
2189 	struct pcn_softc *sc = ifp->if_softc;
2190 
2191 	if ((sc->sc_mii.mii_media_active & IFM_FDX) != 0)
2192 		pcn_bcr_write(sc, LE_BCR9, LE_B9_FDEN);
2193 	else
2194 		pcn_bcr_write(sc, LE_BCR9, 0);
2195 }
2196