xref: /netbsd/sys/arch/sparc/dev/sbus.c (revision 6550d01e)
1 /*	$NetBSD: sbus.c,v 1.74 2010/01/03 23:03:20 mrg Exp $ */
2 
3 /*-
4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Paul Kranenburg.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1992, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * This software was developed by the Computer Systems Engineering group
37  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
38  * contributed to Berkeley.
39  *
40  * All advertising materials mentioning features or use of this software
41  * must display the following acknowledgement:
42  *	This product includes software developed by the University of
43  *	California, Lawrence Berkeley Laboratory.
44  *
45  * Redistribution and use in source and binary forms, with or without
46  * modification, are permitted provided that the following conditions
47  * are met:
48  * 1. Redistributions of source code must retain the above copyright
49  *    notice, this list of conditions and the following disclaimer.
50  * 2. Redistributions in binary form must reproduce the above copyright
51  *    notice, this list of conditions and the following disclaimer in the
52  *    documentation and/or other materials provided with the distribution.
53  * 3. Neither the name of the University nor the names of its contributors
54  *    may be used to endorse or promote products derived from this software
55  *    without specific prior written permission.
56  *
57  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
58  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
59  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
60  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
61  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
62  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
63  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
64  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
65  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
66  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
67  * SUCH DAMAGE.
68  *
69  *	@(#)sbus.c	8.1 (Berkeley) 6/11/93
70  */
71 
72 /*
73  * Sbus stuff.
74  */
75 
76 #include <sys/cdefs.h>
77 __KERNEL_RCSID(0, "$NetBSD: sbus.c,v 1.74 2010/01/03 23:03:20 mrg Exp $");
78 
79 #include <sys/param.h>
80 #include <sys/malloc.h>
81 #include <sys/kernel.h>
82 #include <sys/systm.h>
83 #include <sys/device.h>
84 
85 #include <uvm/uvm_extern.h>
86 
87 #include <machine/autoconf.h>
88 #include <machine/bus.h>
89 #include <sparc/dev/sbusreg.h>
90 #include <dev/sbus/sbusvar.h>
91 #include <dev/sbus/xboxvar.h>
92 
93 #include <sparc/sparc/iommuvar.h>
94 
95 void sbusreset(int);
96 
97 static int sbus_get_intr(struct sbus_softc *, int,
98 			 struct openprom_intr **, int *);
99 static void *sbus_intr_establish(
100 		bus_space_tag_t,
101 		int,			/* Sbus interrupt level */
102 		int,			/* `device class' priority */
103 		int (*)(void *),	/* handler */
104 		void *,			/* handler arg */
105 		void (*)(void));	/* fast handler */
106 
107 
108 /* autoconfiguration driver */
109 int	sbus_match_mainbus(device_t, struct cfdata *, void *);
110 int	sbus_match_iommu(device_t, struct cfdata *, void *);
111 int	sbus_match_xbox(device_t, struct cfdata *, void *);
112 void	sbus_attach_mainbus(device_t, device_t, void *);
113 void	sbus_attach_iommu(device_t, device_t, void *);
114 void	sbus_attach_xbox(device_t, device_t, void *);
115 
116 static	int sbus_error(void);
117 int	(*sbuserr_handler)(void);
118 
119 CFATTACH_DECL_NEW(sbus_mainbus, sizeof(struct sbus_softc),
120     sbus_match_mainbus, sbus_attach_mainbus, NULL, NULL);
121 
122 CFATTACH_DECL_NEW(sbus_iommu, sizeof(struct sbus_softc),
123     sbus_match_iommu, sbus_attach_iommu, NULL, NULL);
124 
125 CFATTACH_DECL_NEW(sbus_xbox, sizeof(struct sbus_softc),
126     sbus_match_xbox, sbus_attach_xbox, NULL, NULL);
127 
128 extern struct cfdriver sbus_cd;
129 
130 static int sbus_mainbus_attached;
131 
132 /* The "primary" Sbus */
133 struct sbus_softc *sbus_sc;
134 
135 /* If the PROM does not provide the `ranges' property, we make up our own */
136 struct openprom_range sbus_translations[] = {
137 	/* Assume a maximum of 4 Sbus slots, all mapped to on-board io space */
138 	{ 0, 0, PMAP_OBIO, SBUS_ADDR(0,0), 1 << 25 },
139 	{ 1, 0, PMAP_OBIO, SBUS_ADDR(1,0), 1 << 25 },
140 	{ 2, 0, PMAP_OBIO, SBUS_ADDR(2,0), 1 << 25 },
141 	{ 3, 0, PMAP_OBIO, SBUS_ADDR(3,0), 1 << 25 }
142 };
143 
144 /*
145  * Child devices receive the Sbus interrupt level in their attach
146  * arguments. We translate these to CPU IPLs using the following
147  * tables. Note: obio bus interrupt levels are identical to the
148  * processor IPL.
149  *
150  * The second set of tables is used when the Sbus interrupt level
151  * cannot be had from the PROM as an `interrupt' property. We then
152  * fall back on the `intr' property which contains the CPU IPL.
153  */
154 
155 /* Translate Sbus interrupt level to processor IPL */
156 static int intr_sbus2ipl_4c[] = {
157 	0, 1, 2, 3, 5, 7, 8, 9
158 };
159 static int intr_sbus2ipl_4m[] = {
160 	0, 2, 3, 5, 7, 9, 11, 13
161 };
162 
163 /*
164  * This value is or'ed into the attach args' interrupt level cookie
165  * if the interrupt level comes from an `intr' property, i.e. it is
166  * not an Sbus interrupt level.
167  */
168 #define SBUS_INTR_COMPAT	0x80000000
169 
170 
171 /*
172  * Print the location of some sbus-attached device (called just
173  * before attaching that device).  If `sbus' is not NULL, the
174  * device was found but not configured; print the sbus as well.
175  * Return UNCONF (config_find ignores this if the device was configured).
176  */
177 int
178 sbus_print(void *args, const char *busname)
179 {
180 	struct sbus_attach_args *sa = args;
181 	int i;
182 
183 	if (busname)
184 		aprint_normal("%s at %s", sa->sa_name, busname);
185 	aprint_normal(" slot %d offset 0x%x", sa->sa_slot, sa->sa_offset);
186 	for (i = 0; i < sa->sa_nintr; i++) {
187 		uint32_t level = sa->sa_intr[i].oi_pri;
188 		struct sbus_softc *sc =
189 			(struct sbus_softc *) sa->sa_bustag->cookie;
190 
191 		aprint_normal(" level %d", level & ~SBUS_INTR_COMPAT);
192 		if ((level & SBUS_INTR_COMPAT) == 0) {
193 			int ipl = sc->sc_intr2ipl[level];
194 			if (ipl != level)
195 				aprint_normal(" (ipl %d)", ipl);
196 		}
197 	}
198 	return (UNCONF);
199 }
200 
201 int
202 sbus_match_mainbus(device_t parent, struct cfdata *cf, void *aux)
203 {
204 	struct mainbus_attach_args *ma = aux;
205 
206 	if (CPU_ISSUN4 || sbus_mainbus_attached)
207 		return (0);
208 
209 	return (strcmp(cf->cf_name, ma->ma_name) == 0);
210 }
211 
212 int
213 sbus_match_iommu(device_t parent, struct cfdata *cf, void *aux)
214 {
215 	struct iommu_attach_args *ia = aux;
216 
217 	if (CPU_ISSUN4)
218 		return (0);
219 
220 	return (strcmp(cf->cf_name, ia->iom_name) == 0);
221 }
222 
223 int
224 sbus_match_xbox(device_t parent, struct cfdata *cf, void *aux)
225 {
226 	struct xbox_attach_args *xa = aux;
227 
228 	if (CPU_ISSUN4)
229 		return (0);
230 
231 	return (strcmp(cf->cf_name, xa->xa_name) == 0);
232 }
233 
234 /*
235  * Attach an Sbus.
236  */
237 void
238 sbus_attach_mainbus(device_t parent, device_t self, void *aux)
239 {
240 	struct sbus_softc *sc = device_private(self);
241 	struct mainbus_attach_args *ma = aux;
242 	int node = ma->ma_node;
243 
244 	sbus_mainbus_attached = 1;
245 
246 	sc->sc_dev = self;
247 	sc->sc_bustag = ma->ma_bustag;
248 	sc->sc_dmatag = ma->ma_dmatag;
249 
250 #if 0	/* sbus at mainbus (sun4c): `reg' prop is not control space */
251 	if (ma->ma_size == 0)
252 		printf("%s: no Sbus registers", device_xname(self));
253 
254 	if (bus_space_map(ma->ma_bustag,
255 			  ma->ma_paddr,
256 			  ma->ma_size,
257 			  BUS_SPACE_MAP_LINEAR,
258 			  &sc->sc_bh) != 0) {
259 		panic("%s: can't map sbusbusreg", device_xname(self));
260 	}
261 #endif
262 
263 	/* Setup interrupt translation tables */
264 	sc->sc_intr2ipl = CPU_ISSUN4C
265 				? intr_sbus2ipl_4c
266 				: intr_sbus2ipl_4m;
267 
268 	/*
269 	 * Record clock frequency for synchronous SCSI.
270 	 * IS THIS THE CORRECT DEFAULT??
271 	 */
272 	sc->sc_clockfreq = prom_getpropint(node, "clock-frequency", 25*1000*1000);
273 	printf(": clock = %s MHz\n", clockfreq(sc->sc_clockfreq));
274 
275 	sbus_sc = sc;
276 	sbus_attach_common(sc, "sbus", node, NULL);
277 }
278 
279 
280 void
281 sbus_attach_iommu(device_t parent, device_t self, void *aux)
282 {
283 	struct sbus_softc *sc = device_private(self);
284 	struct iommu_attach_args *ia = aux;
285 	int node = ia->iom_node;
286 
287 	sc->sc_dev = self;
288 	sc->sc_bustag = ia->iom_bustag;
289 	sc->sc_dmatag = ia->iom_dmatag;
290 
291 	if (ia->iom_nreg == 0)
292 		panic("%s: no Sbus registers", device_xname(self));
293 
294 	if (bus_space_map(ia->iom_bustag,
295 			  BUS_ADDR(ia->iom_reg[0].oa_space,
296 				   ia->iom_reg[0].oa_base),
297 			  (bus_size_t)ia->iom_reg[0].oa_size,
298 			  BUS_SPACE_MAP_LINEAR,
299 			  &sc->sc_bh) != 0) {
300 		panic("%s: can't map sbusbusreg", device_xname(self));
301 	}
302 
303 	/* Setup interrupt translation tables */
304 	sc->sc_intr2ipl = CPU_ISSUN4C ? intr_sbus2ipl_4c : intr_sbus2ipl_4m;
305 
306 	/*
307 	 * Record clock frequency for synchronous SCSI.
308 	 * IS THIS THE CORRECT DEFAULT??
309 	 */
310 	sc->sc_clockfreq = prom_getpropint(node, "clock-frequency", 25*1000*1000);
311 	printf(": clock = %s MHz\n", clockfreq(sc->sc_clockfreq));
312 
313 	sbus_sc = sc;
314 	sbuserr_handler = sbus_error;
315 	sbus_attach_common(sc, "sbus", node, NULL);
316 }
317 
318 void
319 sbus_attach_xbox(device_t parent, device_t self, void *aux)
320 {
321 	struct sbus_softc *sc = device_private(self);
322 	struct xbox_attach_args *xa = aux;
323 	int node = xa->xa_node;
324 
325 	sc->sc_bustag = xa->xa_bustag;
326 	sc->sc_dmatag = xa->xa_dmatag;
327 
328 	/* Setup interrupt translation tables */
329 	sc->sc_intr2ipl = CPU_ISSUN4C ? intr_sbus2ipl_4c : intr_sbus2ipl_4m;
330 
331 	/*
332 	 * Record clock frequency for synchronous SCSI.
333 	 * IS THIS THE CORRECT DEFAULT??
334 	 */
335 	sc->sc_clockfreq = prom_getpropint(node, "clock-frequency", 25*1000*1000);
336 	printf(": clock = %s MHz\n", clockfreq(sc->sc_clockfreq));
337 
338 	sbus_attach_common(sc, "sbus", node, NULL);
339 }
340 
341 void
342 sbus_attach_common(struct sbus_softc *sc, const char *busname, int busnode,
343 		   const char * const *specials)
344 {
345 	int node0, node, error;
346 	const char *sp;
347 	const char *const *ssp;
348 	bus_space_tag_t sbt;
349 	struct sbus_attach_args sa;
350 
351 	if ((sbt = bus_space_tag_alloc(sc->sc_bustag, sc)) == NULL) {
352 		printf("%s: attach: out of memory\n",
353 		    device_xname(sc->sc_dev));
354 		return;
355 	}
356 	sbt->sparc_intr_establish = sbus_intr_establish;
357 
358 	/*
359 	 * Get the SBus burst transfer size if burst transfers are supported
360 	 */
361 	sc->sc_burst = prom_getpropint(busnode, "burst-sizes", 0);
362 
363 
364 	if (CPU_ISSUN4M) {
365 		/*
366 		 * Some models (e.g. SS20) erroneously report 64-bit
367 		 * burst capability. We mask it out here for all SUN4Ms,
368 		 * since probably no member of that class supports
369 		 * 64-bit Sbus bursts.
370 		 */
371 		sc->sc_burst &= ~SBUS_BURST_64;
372 	}
373 
374 	/*
375 	 * Collect address translations from the OBP.
376 	 */
377 	error = prom_getprop(busnode, "ranges", sizeof(struct rom_range),
378 			&sbt->nranges, &sbt->ranges);
379 	switch (error) {
380 	case 0:
381 		break;
382 	case ENOENT:
383 		/* Fall back to our own `range' construction */
384 		sbt->ranges = sbus_translations;
385 		sbt->nranges =
386 			sizeof(sbus_translations)/sizeof(sbus_translations[0]);
387 		break;
388 	default:
389 		panic("%s: error getting ranges property",
390 		    device_xname(sc->sc_dev));
391 	}
392 
393 	/*
394 	 * Loop through ROM children, fixing any relative addresses
395 	 * and then configuring each device.
396 	 * `specials' is an array of device names that are treated
397 	 * specially:
398 	 */
399 	node0 = firstchild(busnode);
400 	for (ssp = specials ; ssp != NULL && *(sp = *ssp) != 0; ssp++) {
401 		if ((node = findnode(node0, sp)) == 0) {
402 			panic("could not find %s amongst %s devices",
403 				sp, busname);
404 		}
405 
406 		if (sbus_setup_attach_args(sc, sbt, sc->sc_dmatag,
407 					   node, &sa) != 0) {
408 			panic("sbus_attach: %s: incomplete", sp);
409 		}
410 		(void) config_found(sc->sc_dev, (void *)&sa, sbus_print);
411 		sbus_destroy_attach_args(&sa);
412 	}
413 
414 	for (node = node0; node; node = nextsibling(node)) {
415 		char *name = prom_getpropstring(node, "name");
416 		for (ssp = specials, sp = NULL;
417 		     ssp != NULL && (sp = *ssp) != NULL;
418 		     ssp++)
419 			if (strcmp(name, sp) == 0)
420 				break;
421 
422 		if (sp != NULL)
423 			/* Already configured as an "early" device */
424 			continue;
425 
426 		if (sbus_setup_attach_args(sc, sbt, sc->sc_dmatag,
427 					   node, &sa) != 0) {
428 			printf("sbus_attach: %s: incomplete\n", name);
429 			continue;
430 		}
431 		(void) config_found(sc->sc_dev, (void *)&sa, sbus_print);
432 		sbus_destroy_attach_args(&sa);
433 	}
434 }
435 
436 int
437 sbus_setup_attach_args(struct sbus_softc *sc,
438 		       bus_space_tag_t bustag, bus_dma_tag_t dmatag, int node,
439 		       struct sbus_attach_args *sa)
440 {
441 	int n, error;
442 
443 	memset(sa, 0, sizeof(struct sbus_attach_args));
444 	error = prom_getprop(node, "name", 1, &n, &sa->sa_name);
445 	if (error != 0)
446 		return (error);
447 	sa->sa_name[n] = '\0';
448 
449 	sa->sa_bustag = bustag;
450 	sa->sa_dmatag = dmatag;
451 	sa->sa_node = node;
452 	sa->sa_frequency = sc->sc_clockfreq;
453 
454 	error = prom_getprop(node, "reg", sizeof(struct openprom_addr),
455 			&sa->sa_nreg, &sa->sa_reg);
456 	if (error != 0) {
457 		char buf[32];
458 		if (error != ENOENT ||
459 		    !node_has_property(node, "device_type") ||
460 		    strcmp(prom_getpropstringA(node, "device_type", buf, sizeof buf),
461 			   "hierarchical") != 0)
462 			return (error);
463 	}
464 	for (n = 0; n < sa->sa_nreg; n++) {
465 		/* Convert to relative addressing, if necessary */
466 		uint32_t base = sa->sa_reg[n].oa_base;
467 		if (SBUS_ABS(base)) {
468 			sa->sa_reg[n].oa_space = SBUS_ABS_TO_SLOT(base);
469 			sa->sa_reg[n].oa_base = SBUS_ABS_TO_OFFSET(base);
470 		}
471 	}
472 
473 	if ((error = sbus_get_intr(sc, node, &sa->sa_intr, &sa->sa_nintr)) != 0)
474 		return (error);
475 
476 	error = prom_getprop(node, "address", sizeof(uint32_t),
477 			 &sa->sa_npromvaddrs, &sa->sa_promvaddrs);
478 	if (error != 0 && error != ENOENT)
479 		return (error);
480 
481 	return (0);
482 }
483 
484 void
485 sbus_destroy_attach_args(struct sbus_attach_args *sa)
486 {
487 
488 	if (sa->sa_name != NULL)
489 		free(sa->sa_name, M_DEVBUF);
490 
491 	if (sa->sa_nreg != 0)
492 		free(sa->sa_reg, M_DEVBUF);
493 
494 	if (sa->sa_intr)
495 		free(sa->sa_intr, M_DEVBUF);
496 
497 	if (sa->sa_promvaddrs)
498 		free(sa->sa_promvaddrs, M_DEVBUF);
499 
500 	memset(sa, 0, sizeof(struct sbus_attach_args));/*DEBUG*/
501 }
502 
503 bus_addr_t
504 sbus_bus_addr(bus_space_tag_t t, u_int btype, u_int offset)
505 {
506 
507 	/* XXX: sbus_bus_addr should be g/c'ed */
508 	return (BUS_ADDR(btype, offset));
509 }
510 
511 
512 /*
513  * Get interrupt attributes for an Sbus device.
514  */
515 static int
516 sbus_get_intr(struct sbus_softc *sc, int node,
517 	      struct openprom_intr **ipp, int *np)
518 {
519 	int error, n;
520 	uint32_t *ipl = NULL;
521 
522 	/*
523 	 * The `interrupts' property contains the Sbus interrupt level.
524 	 */
525 	if (prom_getprop(node, "interrupts", sizeof(int), np,
526 			 &ipl) == 0) {
527 		/* Change format to an `struct openprom_intr' array */
528 		struct openprom_intr *ip;
529 		ip = malloc(*np * sizeof(struct openprom_intr), M_DEVBUF,
530 		    M_NOWAIT);
531 		if (ip == NULL) {
532 			free(ipl, M_DEVBUF);
533 			return (ENOMEM);
534 		}
535 		for (n = 0; n < *np; n++) {
536 			ip[n].oi_pri = ipl[n];
537 			ip[n].oi_vec = 0;
538 		}
539 		free(ipl, M_DEVBUF);
540 		*ipp = ip;
541 		return (0);
542 	}
543 
544 	/*
545 	 * Fall back on `intr' property.
546 	 */
547 	*ipp = NULL;
548 	error = prom_getprop(node, "intr", sizeof(struct openprom_intr),
549 			np, ipp);
550 	switch (error) {
551 	case 0:
552 		for (n = *np; n-- > 0;) {
553 			(*ipp)[n].oi_pri &= 0xf;
554 			(*ipp)[n].oi_pri |= SBUS_INTR_COMPAT;
555 		}
556 		break;
557 	case ENOENT:
558 		error = 0;
559 		break;
560 	}
561 
562 	return (error);
563 }
564 
565 
566 /*
567  * Install an interrupt handler for an Sbus device.
568  */
569 static void *
570 sbus_intr_establish(bus_space_tag_t t, int pri, int level,
571 		    int (*handler)(void *), void *arg,
572 		    void (*fastvec)(void))
573 {
574 	struct sbus_softc *sc = t->cookie;
575 	struct intrhand *ih;
576 	int pil;
577 
578 	ih = (struct intrhand *)
579 		malloc(sizeof(struct intrhand), M_DEVBUF, M_NOWAIT);
580 	if (ih == NULL)
581 		return (NULL);
582 
583 	/*
584 	 * Translate Sbus interrupt priority to CPU interrupt level
585 	 */
586 	if ((pri & SBUS_INTR_COMPAT) != 0)
587 		pil = pri & ~SBUS_INTR_COMPAT;
588 	else
589 		pil = sc->sc_intr2ipl[pri];
590 
591 	ih->ih_fun = handler;
592 	ih->ih_arg = arg;
593 	intr_establish(pil, level, ih, fastvec, false);
594 	return (ih);
595 }
596 
597 static int
598 sbus_error(void)
599 {
600 	struct sbus_softc *sc = sbus_sc;
601 	bus_space_handle_t bh = sc->sc_bh;
602 	uint32_t afsr, afva;
603 	char bits[64];
604 static	int straytime, nstray;
605 	int timesince;
606 
607 	afsr = bus_space_read_4(sc->sc_bustag, bh, SBUS_AFSR_REG);
608 	afva = bus_space_read_4(sc->sc_bustag, bh, SBUS_AFAR_REG);
609 	snprintb(bits, sizeof(bits), SBUS_AFSR_BITS, afsr);
610 	printf("sbus error:\n\tAFSR %s\n", bits);
611 	printf("\taddress: 0x%x%x\n", afsr & SBUS_AFSR_PAH, afva);
612 
613 	/* For now, do the same dance as on stray interrupts */
614 	timesince = time_uptime - straytime;
615 	if (timesince <= 10) {
616 		if (++nstray > 9)
617 			panic("too many SBus errors");
618 	} else {
619 		straytime = time_uptime;
620 		nstray = 1;
621 	}
622 
623 	/* Unlock registers and clear interrupt */
624 	bus_space_write_4(sc->sc_bustag, bh, SBUS_AFSR_REG, afsr);
625 
626 	return (0);
627 }
628