xref: /netbsd-src/sys/arch/sparc/dev/sbus.c (revision 627f7eb200a4419d89b531d55fccd2ee3ffdcde0)
1 /*	$NetBSD: sbus.c,v 1.80 2020/11/22 03:55:33 thorpej 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 1.80 2020/11/22 03:55:33 thorpej Exp $");
78 
79 #include <sys/param.h>
80 #include <sys/malloc.h>
81 #include <sys/kmem.h>
82 #include <sys/kernel.h>
83 #include <sys/systm.h>
84 #include <sys/device.h>
85 
86 #include <uvm/uvm_extern.h>
87 
88 #include <machine/autoconf.h>
89 #include <sys/bus.h>
90 #include <sparc/dev/sbusreg.h>
91 #include <dev/sbus/sbusvar.h>
92 #include <dev/sbus/xboxvar.h>
93 
94 #include <sparc/sparc/iommuvar.h>
95 
96 void sbusreset(int);
97 
98 static int sbus_get_intr(struct sbus_softc *, int,
99 			 struct openprom_intr **, int *);
100 static void *sbus_intr_establish(
101 		bus_space_tag_t,
102 		int,			/* Sbus interrupt level */
103 		int,			/* `device class' priority */
104 		int (*)(void *),	/* handler */
105 		void *,			/* handler arg */
106 		void (*)(void));	/* fast handler */
107 
108 
109 /* autoconfiguration driver */
110 int	sbus_match_mainbus(device_t, struct cfdata *, void *);
111 int	sbus_match_iommu(device_t, struct cfdata *, void *);
112 int	sbus_match_xbox(device_t, struct cfdata *, void *);
113 void	sbus_attach_mainbus(device_t, device_t, void *);
114 void	sbus_attach_iommu(device_t, device_t, void *);
115 void	sbus_attach_xbox(device_t, device_t, void *);
116 
117 #if (defined(SUN4M) && !defined(MSIIEP)) || defined(SUN4D)
118 static	int sbus_error(void);
119 extern	int (*sbuserr_handler)(void);
120 #endif
121 
122 CFATTACH_DECL_NEW(sbus_mainbus, sizeof(struct sbus_softc),
123     sbus_match_mainbus, sbus_attach_mainbus, NULL, NULL);
124 
125 CFATTACH_DECL_NEW(sbus_iommu, sizeof(struct sbus_softc),
126     sbus_match_iommu, sbus_attach_iommu, NULL, NULL);
127 
128 CFATTACH_DECL_NEW(sbus_xbox, sizeof(struct sbus_softc),
129     sbus_match_xbox, sbus_attach_xbox, NULL, NULL);
130 
131 extern struct cfdriver sbus_cd;
132 
133 static int sbus_mainbus_attached;
134 
135 /* The "primary" Sbus */
136 struct sbus_softc *sbus_sc;
137 
138 /* If the PROM does not provide the `ranges' property, we make up our own */
139 struct openprom_range sbus_translations[] = {
140 	/* Assume a maximum of 4 Sbus slots, all mapped to on-board io space */
141 	{ 0, 0, PMAP_OBIO, SBUS_ADDR(0,0), 1 << 25 },
142 	{ 1, 0, PMAP_OBIO, SBUS_ADDR(1,0), 1 << 25 },
143 	{ 2, 0, PMAP_OBIO, SBUS_ADDR(2,0), 1 << 25 },
144 	{ 3, 0, PMAP_OBIO, SBUS_ADDR(3,0), 1 << 25 }
145 };
146 
147 /*
148  * Child devices receive the Sbus interrupt level in their attach
149  * arguments. We translate these to CPU IPLs using the following
150  * tables. Note: obio bus interrupt levels are identical to the
151  * processor IPL.
152  *
153  * The second set of tables is used when the Sbus interrupt level
154  * cannot be had from the PROM as an `interrupt' property. We then
155  * fall back on the `intr' property which contains the CPU IPL.
156  */
157 
158 /* Translate Sbus interrupt level to processor IPL */
159 static int intr_sbus2ipl_4c[] = {
160 	0, 1, 2, 3, 5, 7, 8, 9
161 };
162 static int intr_sbus2ipl_4m[] = {
163 	0, 2, 3, 5, 7, 9, 11, 13
164 };
165 
166 /*
167  * This value is or'ed into the attach args' interrupt level cookie
168  * if the interrupt level comes from an `intr' property, i.e. it is
169  * not an Sbus interrupt level.
170  */
171 #define SBUS_INTR_COMPAT	0x80000000
172 
173 
174 /*
175  * Print the location of some sbus-attached device (called just
176  * before attaching that device).  If `sbus' is not NULL, the
177  * device was found but not configured; print the sbus as well.
178  * Return UNCONF (config_find ignores this if the device was configured).
179  */
180 int
181 sbus_print(void *args, const char *busname)
182 {
183 	struct sbus_attach_args *sa = args;
184 	int i;
185 
186 	if (busname)
187 		aprint_normal("%s at %s", sa->sa_name, busname);
188 	aprint_normal(" slot %d offset 0x%x", sa->sa_slot, sa->sa_offset);
189 	for (i = 0; i < sa->sa_nintr; i++) {
190 		uint32_t level = sa->sa_intr[i].oi_pri;
191 		struct sbus_softc *sc =
192 			(struct sbus_softc *) sa->sa_bustag->cookie;
193 
194 		aprint_normal(" level %d", level & ~SBUS_INTR_COMPAT);
195 		if ((level & SBUS_INTR_COMPAT) == 0) {
196 			int ipl = sc->sc_intr2ipl[level];
197 			if (ipl != level)
198 				aprint_normal(" (ipl %d)", ipl);
199 		}
200 	}
201 	return (UNCONF);
202 }
203 
204 int
205 sbus_match_mainbus(device_t parent, struct cfdata *cf, void *aux)
206 {
207 	struct mainbus_attach_args *ma = aux;
208 
209 	if (CPU_ISSUN4 || sbus_mainbus_attached)
210 		return (0);
211 
212 	return (strcmp(cf->cf_name, ma->ma_name) == 0);
213 }
214 
215 int
216 sbus_match_iommu(device_t parent, struct cfdata *cf, void *aux)
217 {
218 	struct iommu_attach_args *ia = aux;
219 
220 	if (CPU_ISSUN4)
221 		return (0);
222 
223 	return (strcmp(cf->cf_name, ia->iom_name) == 0);
224 }
225 
226 int
227 sbus_match_xbox(device_t parent, struct cfdata *cf, void *aux)
228 {
229 	struct xbox_attach_args *xa = aux;
230 
231 	if (CPU_ISSUN4)
232 		return (0);
233 
234 	return (strcmp(cf->cf_name, xa->xa_name) == 0);
235 }
236 
237 /*
238  * Attach an Sbus.
239  */
240 void
241 sbus_attach_mainbus(device_t parent, device_t self, void *aux)
242 {
243 	struct sbus_softc *sc = device_private(self);
244 	struct mainbus_attach_args *ma = aux;
245 	int node = ma->ma_node;
246 
247 	sbus_mainbus_attached = 1;
248 
249 	sc->sc_dev = self;
250 	sc->sc_bustag = ma->ma_bustag;
251 	sc->sc_dmatag = ma->ma_dmatag;
252 
253 #if 0	/* sbus at mainbus (sun4c): `reg' prop is not control space */
254 	if (ma->ma_size == 0)
255 		printf("%s: no Sbus registers", device_xname(self));
256 
257 	if (bus_space_map(ma->ma_bustag,
258 			  ma->ma_paddr,
259 			  ma->ma_size,
260 			  BUS_SPACE_MAP_LINEAR,
261 			  &sc->sc_bh) != 0) {
262 		panic("%s: can't map sbusbusreg", device_xname(self));
263 	}
264 #endif
265 
266 	/* Setup interrupt translation tables */
267 	sc->sc_intr2ipl = CPU_ISSUN4C
268 				? intr_sbus2ipl_4c
269 				: intr_sbus2ipl_4m;
270 
271 	/*
272 	 * Record clock frequency for synchronous SCSI.
273 	 * IS THIS THE CORRECT DEFAULT??
274 	 */
275 	sc->sc_clockfreq = prom_getpropint(node, "clock-frequency", 25*1000*1000);
276 	printf(": clock = %s MHz\n", clockfreq(sc->sc_clockfreq));
277 
278 	sbus_sc = sc;
279 	sbus_attach_common(sc, "sbus", node, NULL);
280 }
281 
282 
283 void
284 sbus_attach_iommu(device_t parent, device_t self, void *aux)
285 {
286 	struct sbus_softc *sc = device_private(self);
287 	struct iommu_attach_args *ia = aux;
288 	int node = ia->iom_node;
289 
290 	sc->sc_dev = self;
291 	sc->sc_bustag = ia->iom_bustag;
292 	sc->sc_dmatag = ia->iom_dmatag;
293 
294 	if (ia->iom_nreg == 0)
295 		panic("%s: no Sbus registers", device_xname(self));
296 
297 	if (bus_space_map(ia->iom_bustag,
298 			  BUS_ADDR(ia->iom_reg[0].oa_space,
299 				   ia->iom_reg[0].oa_base),
300 			  (bus_size_t)ia->iom_reg[0].oa_size,
301 			  BUS_SPACE_MAP_LINEAR,
302 			  &sc->sc_bh) != 0) {
303 		panic("%s: can't map sbusbusreg", device_xname(self));
304 	}
305 
306 	/* Setup interrupt translation tables */
307 	sc->sc_intr2ipl = CPU_ISSUN4C ? intr_sbus2ipl_4c : intr_sbus2ipl_4m;
308 
309 	/*
310 	 * Record clock frequency for synchronous SCSI.
311 	 * IS THIS THE CORRECT DEFAULT??
312 	 */
313 	sc->sc_clockfreq = prom_getpropint(node, "clock-frequency", 25*1000*1000);
314 	printf(": clock = %s MHz\n", clockfreq(sc->sc_clockfreq));
315 
316 	sbus_sc = sc;
317 #if (defined(SUN4M) && !defined(MSIIEP)) || defined(SUN4D)
318 	sbuserr_handler = sbus_error;
319 #endif
320 	sbus_attach_common(sc, "sbus", node, NULL);
321 }
322 
323 void
324 sbus_attach_xbox(device_t parent, device_t self, void *aux)
325 {
326 	struct sbus_softc *sc = device_private(self);
327 	struct xbox_attach_args *xa = aux;
328 	int node = xa->xa_node;
329 
330 	sc->sc_bustag = xa->xa_bustag;
331 	sc->sc_dmatag = xa->xa_dmatag;
332 
333 	/* Setup interrupt translation tables */
334 	sc->sc_intr2ipl = CPU_ISSUN4C ? intr_sbus2ipl_4c : intr_sbus2ipl_4m;
335 
336 	/*
337 	 * Record clock frequency for synchronous SCSI.
338 	 * IS THIS THE CORRECT DEFAULT??
339 	 */
340 	sc->sc_clockfreq = prom_getpropint(node, "clock-frequency", 25*1000*1000);
341 	printf(": clock = %s MHz\n", clockfreq(sc->sc_clockfreq));
342 
343 	sbus_attach_common(sc, "sbus", node, NULL);
344 }
345 
346 void
347 sbus_attach_common(struct sbus_softc *sc, const char *busname, int busnode,
348 		   const char * const *specials)
349 {
350 	int node0, node, error;
351 	const char *sp;
352 	const char *const *ssp;
353 	bus_space_tag_t sbt;
354 	struct sbus_attach_args sa;
355 
356 	if ((sbt = bus_space_tag_alloc(sc->sc_bustag, sc)) == NULL) {
357 		printf("%s: attach: out of memory\n",
358 		    device_xname(sc->sc_dev));
359 		return;
360 	}
361 	sbt->sparc_intr_establish = sbus_intr_establish;
362 
363 	/*
364 	 * Get the SBus burst transfer size if burst transfers are supported
365 	 */
366 	sc->sc_burst = prom_getpropint(busnode, "burst-sizes", 0);
367 
368 
369 	if (CPU_ISSUN4M) {
370 		/*
371 		 * Some models (e.g. SS20) erroneously report 64-bit
372 		 * burst capability. We mask it out here for all SUN4Ms,
373 		 * since probably no member of that class supports
374 		 * 64-bit Sbus bursts.
375 		 */
376 		sc->sc_burst &= ~SBUS_BURST_64;
377 	}
378 
379 	/*
380 	 * Collect address translations from the OBP.
381 	 */
382 	error = prom_getprop(busnode, "ranges", sizeof(struct rom_range),
383 			&sbt->nranges, &sbt->ranges);
384 	switch (error) {
385 	case 0:
386 		break;
387 	case ENOENT:
388 		/* Fall back to our own `range' construction */
389 		sbt->ranges = sbus_translations;
390 		sbt->nranges =
391 			sizeof(sbus_translations)/sizeof(sbus_translations[0]);
392 		break;
393 	default:
394 		panic("%s: error getting ranges property",
395 		    device_xname(sc->sc_dev));
396 	}
397 
398 	/*
399 	 * Loop through ROM children, fixing any relative addresses
400 	 * and then configuring each device.
401 	 * `specials' is an array of device names that are treated
402 	 * specially:
403 	 */
404 	node0 = firstchild(busnode);
405 	for (ssp = specials ; ssp != NULL && *(sp = *ssp) != 0; ssp++) {
406 		if ((node = findnode(node0, sp)) == 0) {
407 			panic("could not find %s amongst %s devices",
408 				sp, busname);
409 		}
410 
411 		if (sbus_setup_attach_args(sc, sbt, sc->sc_dmatag,
412 					   node, &sa) != 0) {
413 			panic("sbus_attach: %s: incomplete", sp);
414 		}
415 		(void) config_found(sc->sc_dev, (void *)&sa, sbus_print);
416 		sbus_destroy_attach_args(&sa);
417 	}
418 
419 	for (node = node0; node; node = nextsibling(node)) {
420 		char *name = prom_getpropstring(node, "name");
421 		for (ssp = specials, sp = NULL;
422 		     ssp != NULL && (sp = *ssp) != NULL;
423 		     ssp++)
424 			if (strcmp(name, sp) == 0)
425 				break;
426 
427 		if (sp != NULL)
428 			/* Already configured as an "early" device */
429 			continue;
430 
431 		if (sbus_setup_attach_args(sc, sbt, sc->sc_dmatag,
432 					   node, &sa) != 0) {
433 			printf("sbus_attach: %s: incomplete\n", name);
434 			continue;
435 		}
436 		(void) config_found(sc->sc_dev, (void *)&sa, sbus_print);
437 		sbus_destroy_attach_args(&sa);
438 	}
439 }
440 
441 int
442 sbus_setup_attach_args(struct sbus_softc *sc,
443 		       bus_space_tag_t bustag, bus_dma_tag_t dmatag, int node,
444 		       struct sbus_attach_args *sa)
445 {
446 	int n, error;
447 
448 	memset(sa, 0, sizeof(struct sbus_attach_args));
449 	error = prom_getprop(node, "name", 1, &n, &sa->sa_name);
450 	if (error != 0)
451 		return (error);
452 	KASSERT(sa->sa_name[n-1] == '\0');
453 
454 	sa->sa_bustag = bustag;
455 	sa->sa_dmatag = dmatag;
456 	sa->sa_node = node;
457 	sa->sa_frequency = sc->sc_clockfreq;
458 
459 	error = prom_getprop(node, "reg", sizeof(struct openprom_addr),
460 			&sa->sa_nreg, &sa->sa_reg);
461 	if (error != 0) {
462 		char buf[32];
463 		if (error != ENOENT ||
464 		    !node_has_property(node, "device_type") ||
465 		    strcmp(prom_getpropstringA(node, "device_type", buf, sizeof buf),
466 			   "hierarchical") != 0)
467 			return (error);
468 	}
469 	for (n = 0; n < sa->sa_nreg; n++) {
470 		/* Convert to relative addressing, if necessary */
471 		uint32_t base = sa->sa_reg[n].oa_base;
472 		if (SBUS_ABS(base)) {
473 			sa->sa_reg[n].oa_space = SBUS_ABS_TO_SLOT(base);
474 			sa->sa_reg[n].oa_base = SBUS_ABS_TO_OFFSET(base);
475 		}
476 	}
477 
478 	if ((error = sbus_get_intr(sc, node, &sa->sa_intr, &sa->sa_nintr)) != 0)
479 		return (error);
480 
481 	error = prom_getprop(node, "address", sizeof(uint32_t),
482 			 &sa->sa_npromvaddrs, &sa->sa_promvaddrs);
483 	if (error != 0 && error != ENOENT)
484 		return (error);
485 
486 	return (0);
487 }
488 
489 void
490 sbus_destroy_attach_args(struct sbus_attach_args *sa)
491 {
492 
493 	if (sa->sa_name != NULL)
494 		free(sa->sa_name, M_DEVBUF);
495 
496 	if (sa->sa_nreg != 0)
497 		free(sa->sa_reg, M_DEVBUF);
498 
499 	if (sa->sa_intr)
500 		free(sa->sa_intr, M_DEVBUF);
501 
502 	if (sa->sa_promvaddrs)
503 		free(sa->sa_promvaddrs, M_DEVBUF);
504 
505 	memset(sa, 0, sizeof(struct sbus_attach_args));/*DEBUG*/
506 }
507 
508 bus_addr_t
509 sbus_bus_addr(bus_space_tag_t t, u_int btype, u_int offset)
510 {
511 
512 	/* XXX: sbus_bus_addr should be g/c'ed */
513 	return (BUS_ADDR(btype, offset));
514 }
515 
516 
517 /*
518  * Get interrupt attributes for an Sbus device.
519  */
520 static int
521 sbus_get_intr(struct sbus_softc *sc, int node,
522 	      struct openprom_intr **ipp, int *np)
523 {
524 	int error, n;
525 	uint32_t *ipl = NULL;
526 
527 	/*
528 	 * The `interrupts' property contains the Sbus interrupt level.
529 	 */
530 	if (prom_getprop(node, "interrupts", sizeof(int), np,
531 			 &ipl) == 0) {
532 		/* Change format to an `struct openprom_intr' array */
533 		struct openprom_intr *ip;
534 		ip = malloc(*np * sizeof(struct openprom_intr), M_DEVBUF,
535 		    M_WAITOK);
536 		for (n = 0; n < *np; n++) {
537 			ip[n].oi_pri = ipl[n];
538 			ip[n].oi_vec = 0;
539 		}
540 		free(ipl, M_DEVBUF);
541 		*ipp = ip;
542 		return (0);
543 	}
544 
545 	/*
546 	 * Fall back on `intr' property.
547 	 */
548 	*ipp = NULL;
549 	error = prom_getprop(node, "intr", sizeof(struct openprom_intr),
550 			np, ipp);
551 	switch (error) {
552 	case 0:
553 		for (n = *np; n-- > 0;) {
554 			(*ipp)[n].oi_pri &= 0xf;
555 			(*ipp)[n].oi_pri |= SBUS_INTR_COMPAT;
556 		}
557 		break;
558 	case ENOENT:
559 		error = 0;
560 		break;
561 	}
562 
563 	return (error);
564 }
565 
566 
567 /*
568  * Install an interrupt handler for an Sbus device.
569  */
570 static void *
571 sbus_intr_establish(bus_space_tag_t t, int pri, int level,
572 		    int (*handler)(void *), void *arg,
573 		    void (*fastvec)(void))
574 {
575 	struct sbus_softc *sc = t->cookie;
576 	struct intrhand *ih;
577 	int pil;
578 
579 	ih = kmem_alloc(sizeof(struct intrhand), KM_SLEEP);
580 
581 	/*
582 	 * Translate Sbus interrupt priority to CPU interrupt level
583 	 */
584 	if ((pri & SBUS_INTR_COMPAT) != 0)
585 		pil = pri & ~SBUS_INTR_COMPAT;
586 	else
587 		pil = sc->sc_intr2ipl[pri];
588 
589 	ih->ih_fun = handler;
590 	ih->ih_arg = arg;
591 	intr_establish(pil, level, ih, fastvec, false);
592 	return (ih);
593 }
594 
595 #if (defined(SUN4M) && !defined(MSIIEP)) || defined(SUN4D)
596 static int
597 sbus_error(void)
598 {
599 	struct sbus_softc *sc = sbus_sc;
600 	bus_space_handle_t bh = sc->sc_bh;
601 	uint32_t afsr, afva;
602 	char bits[64];
603 static	int straytime, nstray;
604 	int timesince;
605 
606 	afsr = bus_space_read_4(sc->sc_bustag, bh, SBUS_AFSR_REG);
607 	afva = bus_space_read_4(sc->sc_bustag, bh, SBUS_AFAR_REG);
608 	snprintb(bits, sizeof(bits), SBUS_AFSR_BITS, afsr);
609 	printf("sbus error:\n\tAFSR %s\n", bits);
610 	printf("\taddress: 0x%x%x\n", afsr & SBUS_AFSR_PAH, afva);
611 
612 	/* For now, do the same dance as on stray interrupts */
613 	timesince = time_uptime - straytime;
614 	if (timesince <= 10) {
615 		if (++nstray > 9)
616 			panic("too many SBus errors");
617 	} else {
618 		straytime = time_uptime;
619 		nstray = 1;
620 	}
621 
622 	/* Unlock registers and clear interrupt */
623 	bus_space_write_4(sc->sc_bustag, bh, SBUS_AFSR_REG, afsr);
624 
625 	return (0);
626 }
627 #endif
628