xref: /freebsd-12.1/sys/dev/vx/if_vx.c (revision 052d3c12)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1994 Herb Peyerl <[email protected]>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *      This product includes software developed by Herb Peyerl.
18  * 4. The name of Herb Peyerl may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  *
32  *
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 /*
39  * Created from if_ep.c driver by Fred Gray ([email protected]) to support
40  * the 3c590 family.
41  */
42 
43 /*
44  *	Modified from the FreeBSD 1.1.5.1 version by:
45  *		 	Andres Vega Garcia
46  *			INRIA - Sophia Antipolis, France
47  *			[email protected]
48  */
49 
50 /*
51  *  Promiscuous mode added and interrupt logic slightly changed
52  *  to reduce the number of adapter failures. Transceiver select
53  *  logic changed to use value from EEPROM. Autoconfiguration
54  *  features added.
55  *  Done by:
56  *          Serge Babkin
57  *          Chelindbank (Chelyabinsk, Russia)
58  *          [email protected]
59  */
60 
61 
62 #include <sys/param.h>
63 #include <sys/systm.h>
64 #include <sys/sockio.h>
65 #include <sys/kernel.h>
66 #include <sys/malloc.h>
67 #include <sys/mbuf.h>
68 #include <sys/socket.h>
69 
70 #include <net/if.h>
71 #include <net/if_var.h>
72 
73 #include <net/ethernet.h>
74 #include <net/if_dl.h>
75 #include <net/if_types.h>
76 
77 #include <machine/bus.h>
78 
79 #include <sys/bus.h>
80 
81 #include <net/bpf.h>
82 
83 #include <dev/vx/if_vxreg.h>
84 #include <dev/vx/if_vxvar.h>
85 
86 #define ETHER_MAX_LEN	1518
87 #define ETHER_ADDR_LEN	6
88 #define ETHER_ALIGN 	2
89 
90 static struct connector_entry {
91 	int bit;
92 	char *name;
93 } conn_tab[VX_CONNECTORS] = {
94 
95 #define CONNECTOR_UTP	0
96 	{
97 		0x08, "utp"
98 	},
99 #define CONNECTOR_AUI	1
100 	{
101 		0x20, "aui"
102 	},
103 /* dummy */
104 	{
105 		0, "???"
106 	},
107 #define CONNECTOR_BNC	3
108 	{
109 		0x10, "bnc"
110 	},
111 #define CONNECTOR_TX	4
112 	{
113 		0x02, "tx"
114 	},
115 #define CONNECTOR_FX	5
116 	{
117 		0x04, "fx"
118 	},
119 #define CONNECTOR_MII	6
120 	{
121 		0x40, "mii"
122 	},
123 	{
124 		0, "???"
125 	}
126 };
127 
128 static void vx_txstat(struct vx_softc *);
129 static int vx_status(struct vx_softc *);
130 static void vx_init(void *);
131 static void vx_init_locked(struct vx_softc *);
132 static int vx_ioctl(struct ifnet *, u_long, caddr_t);
133 static void vx_start(struct ifnet *);
134 static void vx_start_locked(struct ifnet *);
135 static void vx_watchdog(void *);
136 static void vx_reset(struct vx_softc *);
137 static void vx_read(struct vx_softc *);
138 static struct mbuf *vx_get(struct vx_softc *, u_int);
139 static void vx_mbuf_fill(void *);
140 static void vx_mbuf_empty(struct vx_softc *);
141 static void vx_setfilter(struct vx_softc *);
142 static void vx_getlink(struct vx_softc *);
143 static void vx_setlink(struct vx_softc *);
144 
145 int
146 vx_attach(device_t dev)
147 {
148 	struct vx_softc *sc = device_get_softc(dev);
149 	struct ifnet *ifp;
150 	int i;
151 	u_char eaddr[6];
152 
153 	ifp = sc->vx_ifp = if_alloc(IFT_ETHER);
154 	if (ifp == NULL) {
155 		device_printf(dev, "can not if_alloc()\n");
156 		return 0;
157 	}
158 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
159 
160 	mtx_init(&sc->vx_mtx, device_get_nameunit(dev), MTX_NETWORK_LOCK,
161 	    MTX_DEF);
162 	callout_init_mtx(&sc->vx_callout, &sc->vx_mtx, 0);
163 	callout_init_mtx(&sc->vx_watchdog, &sc->vx_mtx, 0);
164 	GO_WINDOW(0);
165 	CSR_WRITE_2(sc, VX_COMMAND, GLOBAL_RESET);
166 	VX_BUSY_WAIT;
167 
168 	vx_getlink(sc);
169 
170 	/*
171          * Read the station address from the eeprom
172          */
173 	GO_WINDOW(0);
174 	for (i = 0; i < 3; i++) {
175 		int x;
176 
177 		if (vx_busy_eeprom(sc)) {
178 			mtx_destroy(&sc->vx_mtx);
179 			if_free(ifp);
180 			return 0;
181 		}
182 		CSR_WRITE_2(sc, VX_W0_EEPROM_COMMAND, EEPROM_CMD_RD
183 		    | (EEPROM_OEM_ADDR0 + i));
184 		if (vx_busy_eeprom(sc)) {
185 			mtx_destroy(&sc->vx_mtx);
186 			if_free(ifp);
187 			return 0;
188 		}
189 		x = CSR_READ_2(sc, VX_W0_EEPROM_DATA);
190 		eaddr[(i << 1)] = x >> 8;
191 		eaddr[(i << 1) + 1] = x;
192 	}
193 
194 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
195 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
196 	ifp->if_start = vx_start;
197 	ifp->if_ioctl = vx_ioctl;
198 	ifp->if_init = vx_init;
199 	ifp->if_softc = sc;
200 
201 	ether_ifattach(ifp, eaddr);
202 
203 	sc->vx_tx_start_thresh = 20;	/* probably a good starting point. */
204 
205 	VX_LOCK(sc);
206 	vx_stop(sc);
207 	VX_UNLOCK(sc);
208 
209 	return 1;
210 }
211 
212 /*
213  * The order in here seems important. Otherwise we may not receive
214  * interrupts. ?!
215  */
216 static void
217 vx_init(void *xsc)
218 {
219 	struct vx_softc *sc = (struct vx_softc *)xsc;
220 
221 	VX_LOCK(sc);
222 	vx_init_locked(sc);
223 	VX_UNLOCK(sc);
224 }
225 
226 static void
227 vx_init_locked(struct vx_softc *sc)
228 {
229 	struct ifnet *ifp = sc->vx_ifp;
230 	int i;
231 
232 	VX_LOCK_ASSERT(sc);
233 
234 	VX_BUSY_WAIT;
235 
236 	GO_WINDOW(2);
237 
238 	for (i = 0; i < 6; i++)	/* Reload the ether_addr. */
239 		CSR_WRITE_1(sc, VX_W2_ADDR_0 + i, IF_LLADDR(sc->vx_ifp)[i]);
240 
241 	CSR_WRITE_2(sc, VX_COMMAND, RX_RESET);
242 	VX_BUSY_WAIT;
243 	CSR_WRITE_2(sc, VX_COMMAND, TX_RESET);
244 	VX_BUSY_WAIT;
245 
246 	GO_WINDOW(1);		/* Window 1 is operating window */
247 	for (i = 0; i < 31; i++)
248 		CSR_READ_1(sc, VX_W1_TX_STATUS);
249 
250 	CSR_WRITE_2(sc, VX_COMMAND, SET_RD_0_MASK | S_CARD_FAILURE |
251 	    S_RX_COMPLETE | S_TX_COMPLETE | S_TX_AVAIL);
252 	CSR_WRITE_2(sc, VX_COMMAND, SET_INTR_MASK | S_CARD_FAILURE |
253 	    S_RX_COMPLETE | S_TX_COMPLETE | S_TX_AVAIL);
254 
255 	/*
256          * Attempt to get rid of any stray interrupts that occurred during
257          * configuration.  On the i386 this isn't possible because one may
258          * already be queued.  However, a single stray interrupt is
259          * unimportant.
260          */
261 	CSR_WRITE_2(sc, VX_COMMAND, ACK_INTR | 0xff);
262 
263 	vx_setfilter(sc);
264 	vx_setlink(sc);
265 
266 	CSR_WRITE_2(sc, VX_COMMAND, RX_ENABLE);
267 	CSR_WRITE_2(sc, VX_COMMAND, TX_ENABLE);
268 
269 	vx_mbuf_fill(sc);
270 
271 	/* Interface is now `running', with no output active. */
272 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
273 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
274 	callout_reset(&sc->vx_watchdog, hz, vx_watchdog, sc);
275 
276 	/* Attempt to start output, if any. */
277 	vx_start_locked(ifp);
278 }
279 
280 static void
281 vx_setfilter(struct vx_softc *sc)
282 {
283 	struct ifnet *ifp = sc->vx_ifp;
284 
285 	VX_LOCK_ASSERT(sc);
286 	GO_WINDOW(1);		/* Window 1 is operating window */
287 	CSR_WRITE_2(sc, VX_COMMAND, SET_RX_FILTER |
288 	    FIL_INDIVIDUAL | FIL_BRDCST | FIL_MULTICAST |
289 	    ((ifp->if_flags & IFF_PROMISC) ? FIL_PROMISC : 0));
290 }
291 
292 static void
293 vx_getlink(struct vx_softc *sc)
294 {
295 	int n, k;
296 
297 	GO_WINDOW(3);
298 	sc->vx_connectors = CSR_READ_2(sc, VX_W3_RESET_OPT) & 0x7f;
299 	for (n = 0, k = 0; k < VX_CONNECTORS; k++) {
300 		if (sc->vx_connectors & conn_tab[k].bit) {
301 			if (n > 0)
302 				printf("/");
303 			printf("%s", conn_tab[k].name);
304 			n++;
305 		}
306 	}
307 	if (sc->vx_connectors == 0) {
308 		printf("no connectors!\n");
309 		return;
310 	}
311 	GO_WINDOW(3);
312 	sc->vx_connector =
313 	    (CSR_READ_4(sc, VX_W3_INTERNAL_CFG) & INTERNAL_CONNECTOR_MASK)
314 	    >> INTERNAL_CONNECTOR_BITS;
315 	if (sc->vx_connector & 0x10) {
316 		sc->vx_connector &= 0x0f;
317 		printf("[*%s*]", conn_tab[(int)sc->vx_connector].name);
318 		printf(": disable 'auto select' with DOS util!\n");
319 	} else {
320 		printf("[*%s*]\n", conn_tab[(int)sc->vx_connector].name);
321 	}
322 }
323 
324 static void
325 vx_setlink(struct vx_softc *sc)
326 {
327 	struct ifnet *ifp = sc->vx_ifp;
328 	int i, j, k;
329 	char *reason, *warning;
330 	static int prev_flags;
331 	static signed char prev_conn = -1;
332 
333 	VX_LOCK_ASSERT(sc);
334 	if (prev_conn == -1)
335 		prev_conn = sc->vx_connector;
336 
337 	/*
338          * S.B.
339          *
340          * Now behavior was slightly changed:
341          *
342          * if any of flags link[0-2] is used and its connector is
343          * physically present the following connectors are used:
344          *
345          *   link0 - AUI * highest precedence
346          *   link1 - BNC
347          *   link2 - UTP * lowest precedence
348          *
349          * If none of them is specified then
350          * connector specified in the EEPROM is used
351          * (if present on card or UTP if not).
352          */
353 	i = sc->vx_connector;	/* default in EEPROM */
354 	reason = "default";
355 	warning = NULL;
356 
357 	if (ifp->if_flags & IFF_LINK0) {
358 		if (sc->vx_connectors & conn_tab[CONNECTOR_AUI].bit) {
359 			i = CONNECTOR_AUI;
360 			reason = "link0";
361 		} else {
362 			warning = "aui not present! (link0)";
363 		}
364 	} else if (ifp->if_flags & IFF_LINK1) {
365 		if (sc->vx_connectors & conn_tab[CONNECTOR_BNC].bit) {
366 			i = CONNECTOR_BNC;
367 			reason = "link1";
368 		} else {
369 			warning = "bnc not present! (link1)";
370 		}
371 	} else if (ifp->if_flags & IFF_LINK2) {
372 		if (sc->vx_connectors & conn_tab[CONNECTOR_UTP].bit) {
373 			i = CONNECTOR_UTP;
374 			reason = "link2";
375 		} else {
376 			warning = "utp not present! (link2)";
377 		}
378 	} else if ((sc->vx_connectors & conn_tab[(int)sc->vx_connector].bit) == 0) {
379 		warning = "strange connector type in EEPROM.";
380 		reason = "forced";
381 		i = CONNECTOR_UTP;
382 	}
383 	/* Avoid unnecessary message. */
384 	k = (prev_flags ^ ifp->if_flags) & (IFF_LINK0 | IFF_LINK1 | IFF_LINK2);
385 	if ((k != 0) || (prev_conn != i)) {
386 		if (warning != NULL)
387 			if_printf(ifp, "warning: %s\n", warning);
388 		if_printf(ifp, "selected %s. (%s)\n", conn_tab[i].name, reason);
389 	}
390 	/* Set the selected connector. */
391 	GO_WINDOW(3);
392 	j = CSR_READ_4(sc, VX_W3_INTERNAL_CFG) & ~INTERNAL_CONNECTOR_MASK;
393 	CSR_WRITE_4(sc, VX_W3_INTERNAL_CFG, j | (i << INTERNAL_CONNECTOR_BITS));
394 
395 	/* First, disable all. */
396 	CSR_WRITE_2(sc, VX_COMMAND, STOP_TRANSCEIVER);
397 	DELAY(800);
398 	GO_WINDOW(4);
399 	CSR_WRITE_2(sc, VX_W4_MEDIA_TYPE, 0);
400 
401 	/* Second, enable the selected one. */
402 	switch (i) {
403 	case CONNECTOR_UTP:
404 		GO_WINDOW(4);
405 		CSR_WRITE_2(sc, VX_W4_MEDIA_TYPE, ENABLE_UTP);
406 		break;
407 	case CONNECTOR_BNC:
408 		CSR_WRITE_2(sc, VX_COMMAND, START_TRANSCEIVER);
409 		DELAY(800);
410 		break;
411 	case CONNECTOR_TX:
412 	case CONNECTOR_FX:
413 		GO_WINDOW(4);
414 		CSR_WRITE_2(sc, VX_W4_MEDIA_TYPE, LINKBEAT_ENABLE);
415 		break;
416 	default:		/* AUI and MII fall here */
417 		break;
418 	}
419 	GO_WINDOW(1);
420 
421 	prev_flags = ifp->if_flags;
422 	prev_conn = i;
423 }
424 
425 static void
426 vx_start(struct ifnet *ifp)
427 {
428 	struct vx_softc *sc = ifp->if_softc;
429 
430 	VX_LOCK(sc);
431 	vx_start_locked(ifp);
432 	VX_UNLOCK(sc);
433 }
434 
435 static void
436 vx_start_locked(struct ifnet *ifp)
437 {
438 	struct vx_softc *sc = ifp->if_softc;
439 	struct mbuf *m;
440 	int len, pad;
441 
442 	VX_LOCK_ASSERT(sc);
443 
444 	/* Don't transmit if interface is busy or not running */
445 	if ((sc->vx_ifp->if_drv_flags &
446 	    (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) != IFF_DRV_RUNNING)
447 		return;
448 
449 startagain:
450 	/* Sneak a peek at the next packet */
451 	m = ifp->if_snd.ifq_head;
452 	if (m == NULL) {
453 		return;
454 	}
455 	/* We need to use m->m_pkthdr.len, so require the header */
456 	M_ASSERTPKTHDR(m);
457 	len = m->m_pkthdr.len;
458 
459 	pad = (4 - len) & 3;
460 
461 	/*
462          * The 3c509 automatically pads short packets to minimum ethernet
463 	 * length, but we drop packets that are too large. Perhaps we should
464 	 * truncate them instead?
465          */
466 	if (len + pad > ETHER_MAX_LEN) {
467 		/* packet is obviously too large: toss it */
468 		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
469 		IF_DEQUEUE(&ifp->if_snd, m);
470 		m_freem(m);
471 		goto readcheck;
472 	}
473 	VX_BUSY_WAIT;
474 	if (CSR_READ_2(sc, VX_W1_FREE_TX) < len + pad + 4) {
475 		CSR_WRITE_2(sc, VX_COMMAND,
476 		    SET_TX_AVAIL_THRESH | ((len + pad + 4) >> 2));
477 		/* not enough room in FIFO - make sure */
478 		if (CSR_READ_2(sc, VX_W1_FREE_TX) < len + pad + 4) {
479 			ifp->if_drv_flags |= IFF_DRV_OACTIVE;
480 			sc->vx_timer = 1;
481 			return;
482 		}
483 	}
484 	CSR_WRITE_2(sc, VX_COMMAND, SET_TX_AVAIL_THRESH | (8188 >> 2));
485 	IF_DEQUEUE(&ifp->if_snd, m);
486 	if (m == NULL)		/* not really needed */
487 		return;
488 
489 	VX_BUSY_WAIT;
490 	CSR_WRITE_2(sc, VX_COMMAND, SET_TX_START_THRESH |
491 	    ((len / 4 + sc->vx_tx_start_thresh) >> 2));
492 
493 	BPF_MTAP(sc->vx_ifp, m);
494 
495 	/*
496          * Do the output at splhigh() so that an interrupt from another device
497          * won't cause a FIFO underrun.
498 	 *
499 	 * XXX: Can't enforce that anymore.
500          */
501 
502 	CSR_WRITE_4(sc, VX_W1_TX_PIO_WR_1, len | TX_INDICATE);
503 
504 	while (m) {
505 		if (m->m_len > 3)
506 			bus_space_write_multi_4(sc->vx_bst, sc->vx_bsh,
507 			    VX_W1_TX_PIO_WR_1, (u_int32_t *)mtod(m, caddr_t),
508 			    m->m_len / 4);
509 		if (m->m_len & 3)
510 			bus_space_write_multi_1(sc->vx_bst, sc->vx_bsh,
511 			    VX_W1_TX_PIO_WR_1,
512 			    mtod(m, caddr_t) + (m->m_len & ~3), m->m_len & 3);
513 		m = m_free(m);
514 	}
515 	while (pad--)
516 		CSR_WRITE_1(sc, VX_W1_TX_PIO_WR_1, 0);	/* Padding */
517 
518 	if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
519 	sc->vx_timer = 1;
520 
521 readcheck:
522 	if ((CSR_READ_2(sc, VX_W1_RX_STATUS) & ERR_INCOMPLETE) == 0) {
523 		/* We received a complete packet. */
524 
525 		if ((CSR_READ_2(sc, VX_STATUS) & S_INTR_LATCH) == 0) {
526 			/*
527 		         * No interrupt, read the packet and continue
528 		         * Is this supposed to happen?  Is my motherboard
529 		         * completely busted?
530 		         */
531 			vx_read(sc);
532 		} else
533 			/*
534 			 * Got an interrupt, return so that it gets
535 			 * serviced.
536 			 */
537 			return;
538 	} else {
539 		/* Check if we are stuck and reset [see XXX comment] */
540 		if (vx_status(sc)) {
541 			if (ifp->if_flags & IFF_DEBUG)
542 				if_printf(ifp, "adapter reset\n");
543 			vx_reset(sc);
544 		}
545 	}
546 
547 	goto startagain;
548 }
549 
550 /*
551  * XXX: The 3c509 card can get in a mode where both the fifo status bit
552  *      FIFOS_RX_OVERRUN and the status bit ERR_INCOMPLETE are set
553  *      We detect this situation and we reset the adapter.
554  *      It happens at times when there is a lot of broadcast traffic
555  *      on the cable (once in a blue moon).
556  */
557 static int
558 vx_status(struct vx_softc *sc)
559 {
560 	struct ifnet *ifp;
561 	int fifost;
562 
563 	VX_LOCK_ASSERT(sc);
564 
565 	/*
566          * Check the FIFO status and act accordingly
567          */
568 	GO_WINDOW(4);
569 	fifost = CSR_READ_2(sc, VX_W4_FIFO_DIAG);
570 	GO_WINDOW(1);
571 
572 	ifp = sc->vx_ifp;
573 	if (fifost & FIFOS_RX_UNDERRUN) {
574 		if (ifp->if_flags & IFF_DEBUG)
575 			if_printf(ifp, "RX underrun\n");
576 		vx_reset(sc);
577 		return 0;
578 	}
579 	if (fifost & FIFOS_RX_STATUS_OVERRUN) {
580 		if (ifp->if_flags & IFF_DEBUG)
581 			if_printf(ifp, "RX Status overrun\n");
582 		return 1;
583 	}
584 	if (fifost & FIFOS_RX_OVERRUN) {
585 		if (ifp->if_flags & IFF_DEBUG)
586 			if_printf(ifp, "RX overrun\n");
587 		return 1;
588 	}
589 	if (fifost & FIFOS_TX_OVERRUN) {
590 		if (ifp->if_flags & IFF_DEBUG)
591 			if_printf(ifp, "TX overrun\n");
592 		vx_reset(sc);
593 		return 0;
594 	}
595 	return 0;
596 }
597 
598 static void
599 vx_txstat(struct vx_softc *sc)
600 {
601 	struct ifnet *ifp;
602 	int i;
603 
604 	VX_LOCK_ASSERT(sc);
605 
606 	/*
607         * We need to read+write TX_STATUS until we get a 0 status
608         * in order to turn off the interrupt flag.
609         */
610 	ifp = sc->vx_ifp;
611 	while ((i = CSR_READ_1(sc, VX_W1_TX_STATUS)) & TXS_COMPLETE) {
612 		CSR_WRITE_1(sc, VX_W1_TX_STATUS, 0x0);
613 
614 		if (i & TXS_JABBER) {
615 			if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
616 			if (ifp->if_flags & IFF_DEBUG)
617 				if_printf(ifp, "jabber (%x)\n", i);
618 			vx_reset(sc);
619 		} else if (i & TXS_UNDERRUN) {
620 			if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
621 			if (ifp->if_flags & IFF_DEBUG)
622 				if_printf(ifp, "fifo underrun (%x) @%d\n", i,
623 				    sc->vx_tx_start_thresh);
624 			if (sc->vx_tx_succ_ok < 100)
625 				sc->vx_tx_start_thresh =
626 				    min(ETHER_MAX_LEN,
627 					sc->vx_tx_start_thresh + 20);
628 			sc->vx_tx_succ_ok = 0;
629 			vx_reset(sc);
630 		} else if (i & TXS_MAX_COLLISION) {
631 			if_inc_counter(ifp, IFCOUNTER_COLLISIONS, 1);
632 			CSR_WRITE_2(sc, VX_COMMAND, TX_ENABLE);
633 			ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
634 		} else
635 			sc->vx_tx_succ_ok = (sc->vx_tx_succ_ok + 1) & 127;
636 	}
637 }
638 
639 void
640 vx_intr(void *voidsc)
641 {
642 	short status;
643 	struct vx_softc *sc = voidsc;
644 	struct ifnet *ifp = sc->vx_ifp;
645 
646 	VX_LOCK(sc);
647 	for (;;) {
648 		CSR_WRITE_2(sc, VX_COMMAND, C_INTR_LATCH);
649 
650 		status = CSR_READ_2(sc, VX_STATUS);
651 
652 		if ((status & (S_TX_COMPLETE | S_TX_AVAIL |
653 		    S_RX_COMPLETE | S_CARD_FAILURE)) == 0)
654 			break;
655 
656 		/*
657 		 * Acknowledge any interrupts.  It's important that we do this
658 		 * first, since there would otherwise be a race condition.
659 		 * Due to the i386 interrupt queueing, we may get spurious
660 		 * interrupts occasionally.
661 		 */
662 		CSR_WRITE_2(sc, VX_COMMAND, ACK_INTR | status);
663 
664 		if (status & S_RX_COMPLETE)
665 			vx_read(sc);
666 		if (status & S_TX_AVAIL) {
667 			sc->vx_timer = 0;
668 			sc->vx_ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
669 			vx_start_locked(sc->vx_ifp);
670 		}
671 		if (status & S_CARD_FAILURE) {
672 			if_printf(ifp, "adapter failure (%x)\n", status);
673 			sc->vx_timer = 0;
674 			vx_reset(sc);
675 			break;
676 		}
677 		if (status & S_TX_COMPLETE) {
678 			sc->vx_timer = 0;
679 			vx_txstat(sc);
680 			vx_start_locked(ifp);
681 		}
682 	}
683 	VX_UNLOCK(sc);
684 
685 	/* no more interrupts */
686 	return;
687 }
688 
689 static void
690 vx_read(struct vx_softc *sc)
691 {
692 	struct ifnet *ifp = sc->vx_ifp;
693 	struct mbuf *m;
694 	struct ether_header *eh;
695 	u_int len;
696 
697 	VX_LOCK_ASSERT(sc);
698 	len = CSR_READ_2(sc, VX_W1_RX_STATUS);
699 again:
700 
701 	if (ifp->if_flags & IFF_DEBUG) {
702 		int err = len & ERR_MASK;
703 		char *s = NULL;
704 
705 		if (len & ERR_INCOMPLETE)
706 			s = "incomplete packet";
707 		else if (err == ERR_OVERRUN)
708 			s = "packet overrun";
709 		else if (err == ERR_RUNT)
710 			s = "runt packet";
711 		else if (err == ERR_ALIGNMENT)
712 			s = "bad alignment";
713 		else if (err == ERR_CRC)
714 			s = "bad crc";
715 		else if (err == ERR_OVERSIZE)
716 			s = "oversized packet";
717 		else if (err == ERR_DRIBBLE)
718 			s = "dribble bits";
719 
720 		if (s)
721 			if_printf(ifp, "%s\n", s);
722 	}
723 	if (len & ERR_INCOMPLETE)
724 		return;
725 
726 	if (len & ERR_RX) {
727 		if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
728 		goto abort;
729 	}
730 	len &= RX_BYTES_MASK;	/* Lower 11 bits = RX bytes. */
731 
732 	/* Pull packet off interface. */
733 	m = vx_get(sc, len);
734 	if (m == NULL) {
735 		if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
736 		goto abort;
737 	}
738 	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
739 
740 	{
741 		struct mbuf *m0;
742 
743 		m0 = m_devget(mtod(m, char *), m->m_pkthdr.len, ETHER_ALIGN,
744 		    ifp, NULL);
745 		if (m0 == NULL) {
746 			if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
747 			goto abort;
748 		}
749 		m_freem(m);
750 		m = m0;
751 	}
752 
753 	/* We assume the header fit entirely in one mbuf. */
754 	eh = mtod(m, struct ether_header *);
755 
756 	/*
757          * XXX: Some cards seem to be in promiscuous mode all the time.
758          * we need to make sure we only get our own stuff always.
759          * bleah!
760          */
761 
762 	if (!(ifp->if_flags & IFF_PROMISC)
763 	    && (eh->ether_dhost[0] & 1) == 0	/* !mcast and !bcast */
764 	    && bcmp(eh->ether_dhost, IF_LLADDR(sc->vx_ifp),
765 	    ETHER_ADDR_LEN) != 0) {
766 		m_freem(m);
767 		return;
768 	}
769 	VX_UNLOCK(sc);
770 	(*ifp->if_input)(ifp, m);
771 	VX_LOCK(sc);
772 
773 	/*
774         * In periods of high traffic we can actually receive enough
775         * packets so that the fifo overrun bit will be set at this point,
776         * even though we just read a packet. In this case we
777         * are not going to receive any more interrupts. We check for
778         * this condition and read again until the fifo is not full.
779         * We could simplify this test by not using vx_status(), but
780         * rechecking the RX_STATUS register directly. This test could
781         * result in unnecessary looping in cases where there is a new
782         * packet but the fifo is not full, but it will not fix the
783         * stuck behavior.
784         *
785         * Even with this improvement, we still get packet overrun errors
786         * which are hurting performance. Maybe when I get some more time
787         * I'll modify vx_read() so that it can handle RX_EARLY interrupts.
788         */
789 	if (vx_status(sc)) {
790 		len = CSR_READ_2(sc, VX_W1_RX_STATUS);
791 		/* Check if we are stuck and reset [see XXX comment] */
792 		if (len & ERR_INCOMPLETE) {
793 			if (ifp->if_flags & IFF_DEBUG)
794 				if_printf(ifp, "adapter reset\n");
795 			vx_reset(sc);
796 			return;
797 		}
798 		goto again;
799 	}
800 	return;
801 
802 abort:
803 	CSR_WRITE_2(sc, VX_COMMAND, RX_DISCARD_TOP_PACK);
804 }
805 
806 static struct mbuf *
807 vx_get(struct vx_softc *sc, u_int totlen)
808 {
809 	struct ifnet *ifp = sc->vx_ifp;
810 	struct mbuf *top, **mp, *m;
811 	int len;
812 
813 	VX_LOCK_ASSERT(sc);
814 	m = sc->vx_mb[sc->vx_next_mb];
815 	sc->vx_mb[sc->vx_next_mb] = NULL;
816 	if (m == NULL) {
817 		MGETHDR(m, M_NOWAIT, MT_DATA);
818 		if (m == NULL)
819 			return NULL;
820 	} else {
821 		/* If the queue is no longer full, refill. */
822 		if (sc->vx_last_mb == sc->vx_next_mb &&
823 		    sc->vx_buffill_pending == 0) {
824 			callout_reset(&sc->vx_callout, hz / 100, vx_mbuf_fill,
825 			    sc);
826 			sc->vx_buffill_pending = 1;
827 		}
828 		/* Convert one of our saved mbuf's. */
829 		sc->vx_next_mb = (sc->vx_next_mb + 1) % MAX_MBS;
830 		m->m_data = m->m_pktdat;
831 		m->m_flags = M_PKTHDR;
832 		bzero(&m->m_pkthdr, sizeof(m->m_pkthdr));
833 	}
834 	m->m_pkthdr.rcvif = ifp;
835 	m->m_pkthdr.len = totlen;
836 	len = MHLEN;
837 	top = NULL;
838 	mp = &top;
839 
840 	/*
841          * We read the packet at splhigh() so that an interrupt from another
842          * device doesn't cause the card's buffer to overflow while we're
843          * reading it.  We may still lose packets at other times.
844 	 *
845 	 * XXX: Can't enforce this anymore.
846          */
847 
848 	/*
849          * Since we don't set allowLargePackets bit in MacControl register,
850          * we can assume that totlen <= 1500bytes.
851          * The while loop will be performed iff we have a packet with
852          * MLEN < m_len < MINCLSIZE.
853          */
854 	while (totlen > 0) {
855 		if (top) {
856 			m = sc->vx_mb[sc->vx_next_mb];
857 			sc->vx_mb[sc->vx_next_mb] = NULL;
858 			if (m == NULL) {
859 				MGET(m, M_NOWAIT, MT_DATA);
860 				if (m == NULL) {
861 					m_freem(top);
862 					return NULL;
863 				}
864 			} else {
865 				sc->vx_next_mb = (sc->vx_next_mb + 1) % MAX_MBS;
866 			}
867 			len = MLEN;
868 		}
869 		if (totlen >= MINCLSIZE) {
870 			if (MCLGET(m, M_NOWAIT))
871 				len = MCLBYTES;
872 		}
873 		len = min(totlen, len);
874 		if (len > 3)
875 			bus_space_read_multi_4(sc->vx_bst, sc->vx_bsh,
876 			    VX_W1_RX_PIO_RD_1, mtod(m, u_int32_t *), len / 4);
877 		if (len & 3) {
878 			bus_space_read_multi_1(sc->vx_bst, sc->vx_bsh,
879 			    VX_W1_RX_PIO_RD_1, mtod(m, u_int8_t *) + (len & ~3),
880 			    len & 3);
881 		}
882 		m->m_len = len;
883 		totlen -= len;
884 		*mp = m;
885 		mp = &m->m_next;
886 	}
887 
888 	CSR_WRITE_2(sc, VX_COMMAND, RX_DISCARD_TOP_PACK);
889 
890 	return top;
891 }
892 
893 
894 static int
895 vx_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
896 {
897 	struct vx_softc *sc = ifp->if_softc;
898 	struct ifreq *ifr = (struct ifreq *) data;
899 	int error = 0;
900 
901 	switch (cmd) {
902 	case SIOCSIFFLAGS:
903 		VX_LOCK(sc);
904 		if ((ifp->if_flags & IFF_UP) == 0 &&
905 		    (ifp->if_drv_flags & IFF_DRV_RUNNING) != 0) {
906 			/*
907 	                 * If interface is marked up and it is stopped, then
908 	                 * start it.
909 	                 */
910 			vx_stop(sc);
911 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
912 		} else if ((ifp->if_flags & IFF_UP) != 0 &&
913 		    (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
914 			/*
915 	                 * If interface is marked up and it is stopped, then
916 	                 * start it.
917 	                 */
918 			vx_init_locked(sc);
919 		} else {
920 			/*
921 	                 * deal with flags changes:
922 	                 * IFF_MULTICAST, IFF_PROMISC,
923 	                 * IFF_LINK0, IFF_LINK1,
924 	                 */
925 			vx_setfilter(sc);
926 			vx_setlink(sc);
927 		}
928 		VX_UNLOCK(sc);
929 		break;
930 
931 	case SIOCSIFMTU:
932 		/*
933 	         * Set the interface MTU.
934 	         */
935 		VX_LOCK(sc);
936 		if (ifr->ifr_mtu > ETHERMTU) {
937 			error = EINVAL;
938 		} else {
939 			ifp->if_mtu = ifr->ifr_mtu;
940 		}
941 		VX_UNLOCK(sc);
942 		break;
943 
944 	case SIOCADDMULTI:
945 	case SIOCDELMULTI:
946 		/*
947 		 * Multicast list has changed; set the hardware filter
948 		 * accordingly.
949 		 */
950 		VX_LOCK(sc);
951 		vx_reset(sc);
952 		VX_UNLOCK(sc);
953 		error = 0;
954 		break;
955 
956 
957 	default:
958 		error = ether_ioctl(ifp, cmd, data);
959 		break;
960 	}
961 
962 	return (error);
963 }
964 
965 static void
966 vx_reset(struct vx_softc *sc)
967 {
968 
969 	VX_LOCK_ASSERT(sc);
970 	vx_stop(sc);
971 	vx_init_locked(sc);
972 }
973 
974 static void
975 vx_watchdog(void *arg)
976 {
977 	struct vx_softc *sc;
978 	struct ifnet *ifp;
979 
980 	sc = arg;
981 	VX_LOCK_ASSERT(sc);
982 	callout_reset(&sc->vx_watchdog, hz, vx_watchdog, sc);
983 	if (sc->vx_timer == 0 || --sc->vx_timer > 0)
984 		return;
985 
986 	ifp = sc->vx_ifp;
987 	if (ifp->if_flags & IFF_DEBUG)
988 		if_printf(ifp, "device timeout\n");
989 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
990 	vx_start_locked(ifp);
991 	vx_intr(sc);
992 }
993 
994 void
995 vx_stop(struct vx_softc *sc)
996 {
997 
998 	VX_LOCK_ASSERT(sc);
999 	sc->vx_timer = 0;
1000 	callout_stop(&sc->vx_watchdog);
1001 
1002 	CSR_WRITE_2(sc, VX_COMMAND, RX_DISABLE);
1003 	CSR_WRITE_2(sc, VX_COMMAND, RX_DISCARD_TOP_PACK);
1004 	VX_BUSY_WAIT;
1005 	CSR_WRITE_2(sc, VX_COMMAND, TX_DISABLE);
1006 	CSR_WRITE_2(sc, VX_COMMAND, STOP_TRANSCEIVER);
1007 	DELAY(800);
1008 	CSR_WRITE_2(sc, VX_COMMAND, RX_RESET);
1009 	VX_BUSY_WAIT;
1010 	CSR_WRITE_2(sc, VX_COMMAND, TX_RESET);
1011 	VX_BUSY_WAIT;
1012 	CSR_WRITE_2(sc, VX_COMMAND, C_INTR_LATCH);
1013 	CSR_WRITE_2(sc, VX_COMMAND, SET_RD_0_MASK);
1014 	CSR_WRITE_2(sc, VX_COMMAND, SET_INTR_MASK);
1015 	CSR_WRITE_2(sc, VX_COMMAND, SET_RX_FILTER);
1016 
1017 	vx_mbuf_empty(sc);
1018 }
1019 
1020 int
1021 vx_busy_eeprom(struct vx_softc *sc)
1022 {
1023 	int j, i = 100;
1024 
1025 	while (i--) {
1026 		j = CSR_READ_2(sc, VX_W0_EEPROM_COMMAND);
1027 		if (j & EEPROM_BUSY)
1028 			DELAY(100);
1029 		else
1030 			break;
1031 	}
1032 	if (!i) {
1033 		if_printf(sc->vx_ifp, "eeprom failed to come ready\n");
1034 		return (1);
1035 	}
1036 	return (0);
1037 }
1038 
1039 static void
1040 vx_mbuf_fill(void *sp)
1041 {
1042 	struct vx_softc *sc = (struct vx_softc *)sp;
1043 	int i;
1044 
1045 	VX_LOCK_ASSERT(sc);
1046 	i = sc->vx_last_mb;
1047 	do {
1048 		if (sc->vx_mb[i] == NULL)
1049 			MGET(sc->vx_mb[i], M_NOWAIT, MT_DATA);
1050 		if (sc->vx_mb[i] == NULL)
1051 			break;
1052 		i = (i + 1) % MAX_MBS;
1053 	} while (i != sc->vx_next_mb);
1054 	sc->vx_last_mb = i;
1055 	/* If the queue was not filled, try again. */
1056 	if (sc->vx_last_mb != sc->vx_next_mb) {
1057 		callout_reset(&sc->vx_callout, hz / 100, vx_mbuf_fill, sc);
1058 		sc->vx_buffill_pending = 1;
1059 	} else {
1060 		sc->vx_buffill_pending = 0;
1061 	}
1062 }
1063 
1064 static void
1065 vx_mbuf_empty(struct vx_softc *sc)
1066 {
1067 	int i;
1068 
1069 	VX_LOCK_ASSERT(sc);
1070 	for (i = 0; i < MAX_MBS; i++) {
1071 		if (sc->vx_mb[i]) {
1072 			m_freem(sc->vx_mb[i]);
1073 			sc->vx_mb[i] = NULL;
1074 		}
1075 	}
1076 	sc->vx_last_mb = sc->vx_next_mb = 0;
1077 	if (sc->vx_buffill_pending != 0)
1078 		callout_stop(&sc->vx_callout);
1079 }
1080