xref: /freebsd/sys/dev/bhnd/bhnd_erom.c (revision ca942ab4b2b665e5375cc72afc4930d3b33b14f9)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2016 Landon Fuller <landonf@FreeBSD.org>
5  * Copyright (c) 2017 The FreeBSD Foundation
6  * All rights reserved.
7  *
8  * Portions of this software were developed by Landon Fuller
9  * under sponsorship from the FreeBSD Foundation.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
19  *    redistribution must be conditioned upon including a substantially
20  *    similar Disclaimer requirement for further binary redistribution.
21  *
22  * NO WARRANTY
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
26  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
27  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
28  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
31  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
33  * THE POSSIBILITY OF SUCH DAMAGES.
34  */
35 
36 #include <sys/param.h>
37 #include <sys/bus.h>
38 #include <sys/kobj.h>
39 
40 #include <machine/bus.h>
41 #include <sys/rman.h>
42 #include <machine/resource.h>
43 
44 #include <dev/bhnd/bhndreg.h>
45 #include <dev/bhnd/bhndvar.h>
46 
47 #include <dev/bhnd/bhnd_erom.h>
48 #include <dev/bhnd/bhnd_eromvar.h>
49 
50 #include <dev/bhnd/cores/chipc/chipcreg.h>
51 
52 static int	bhnd_erom_iores_map(struct bhnd_erom_io *eio, bhnd_addr_t addr,
53 		    bhnd_size_t size);
54 static int	bhnd_erom_iores_tell(struct bhnd_erom_io *eio,
55 		    bhnd_addr_t *addr, bhnd_size_t *size);
56 static uint32_t	bhnd_erom_iores_read(struct bhnd_erom_io *eio,
57 		    bhnd_size_t offset, u_int width);
58 static void	bhnd_erom_iores_fini(struct bhnd_erom_io *eio);
59 
60 static int	bhnd_erom_iobus_map(struct bhnd_erom_io *eio, bhnd_addr_t addr,
61 		    bhnd_size_t size);
62 static int	bhnd_erom_iobus_tell(struct bhnd_erom_io *eio,
63 		    bhnd_addr_t *addr, bhnd_size_t *size);
64 static uint32_t	bhnd_erom_iobus_read(struct bhnd_erom_io *eio,
65 		    bhnd_size_t offset, u_int width);
66 
67 /**
68  * An implementation of bhnd_erom_io that manages mappings via
69  * bhnd_alloc_resource() and bhnd_release_resource().
70  */
71 struct bhnd_erom_iores {
72 	struct bhnd_erom_io	 eio;
73 	device_t		 owner;		/**< device from which we'll allocate resources */
74 	int			 owner_rid;	/**< rid to use when allocating new mappings */
75 	struct bhnd_resource	*mapped;	/**< current mapping, or NULL */
76 };
77 
78 /**
79  * Fetch the device enumeration parser class from all bhnd(4)-compatible drivers
80  * registered for @p bus_devclass, probe @p eio for supporting parser classes,
81  * and return the best available supporting enumeration parser class.
82  *
83  * @param	bus_devclass	The bus device class to be queried for
84  *				bhnd(4)-compatible drivers.
85  * @param	eio		An erom bus I/O instance, configured with a
86  *				mapping of the first bus core.
87  * @param	hint		Identification hint used to identify the device.
88  *				If the chipset supports standard chip
89  *				identification registers within the first core,
90  *				this parameter should be NULL.
91  * @param[out]	cid		On success, the probed chip identifier.
92  *
93  * @retval non-NULL	on success, the best available EROM class.
94  * @retval NULL		if no erom class returned a successful probe result for
95  *			@p eio.
96  */
97 bhnd_erom_class_t *
bhnd_erom_probe_driver_classes(devclass_t bus_devclass,struct bhnd_erom_io * eio,const struct bhnd_chipid * hint,struct bhnd_chipid * cid)98 bhnd_erom_probe_driver_classes(devclass_t bus_devclass,
99     struct bhnd_erom_io *eio, const struct bhnd_chipid *hint,
100     struct bhnd_chipid *cid)
101 {
102 	driver_t		**drivers;
103 	int			 drv_count;
104 	bhnd_erom_class_t	*erom_cls;
105 	int			 error, prio, result;
106 
107 	erom_cls = NULL;
108 	prio = 0;
109 
110 	/* Fetch all available drivers */
111 	error = devclass_get_drivers(bus_devclass, &drivers, &drv_count);
112 	if (error) {
113 		printf("error fetching bhnd(4) drivers for %s: %d\n",
114 		    devclass_get_name(bus_devclass), error);
115 		return (NULL);
116 	}
117 
118 	/* Enumerate the drivers looking for the best available EROM class */
119 	for (int i = 0; i < drv_count; i++) {
120 		struct bhnd_chipid	 pcid;
121 		bhnd_erom_class_t	*cls;
122 
123 		/* The default implementation of BHND_BUS_GET_EROM_CLASS()
124 		 * returns NULL if unimplemented; this should always be safe
125 		 * to call on arbitrary drivers */
126 		cls = bhnd_driver_get_erom_class(drivers[i]);
127 		if (cls == NULL)
128 			continue;
129 
130 		kobj_class_compile(cls);
131 
132 		/* Probe the bus */
133 		result = bhnd_erom_probe(cls, eio, hint, &pcid);
134 
135 		/* The parser did not match if an error was returned */
136 		if (result > 0)
137 			continue;
138 
139 		/* Check for a new highest priority match */
140 		if (erom_cls == NULL || result > prio) {
141 			prio = result;
142 
143 			*cid = pcid;
144 			erom_cls = cls;
145 		}
146 
147 		/* Terminate immediately on BUS_PROBE_SPECIFIC */
148 		if (result == BUS_PROBE_SPECIFIC)
149 			break;
150 	}
151 
152 	free(drivers, M_TEMP);
153 	return (erom_cls);
154 }
155 
156 /**
157  * Allocate and return a new device enumeration table parser.
158  *
159  * @param cls		The parser class for which an instance will be
160  *			allocated.
161  * @param eio		The bus I/O callbacks to use when reading the device
162  *			enumeration table.
163  * @param cid		The device's chip identifier.
164  *
165  * @retval non-NULL	success
166  * @retval NULL		if an error occurred allocating or initializing the
167  *			EROM parser.
168  */
169 bhnd_erom_t *
bhnd_erom_alloc(bhnd_erom_class_t * cls,const struct bhnd_chipid * cid,struct bhnd_erom_io * eio)170 bhnd_erom_alloc(bhnd_erom_class_t *cls, const struct bhnd_chipid *cid,
171     struct bhnd_erom_io *eio)
172 {
173 	bhnd_erom_t	*erom;
174 	int		 error;
175 
176 	erom = (bhnd_erom_t *)kobj_create((kobj_class_t)cls, M_BHND,
177 	    M_WAITOK|M_ZERO);
178 
179 	if ((error = BHND_EROM_INIT(erom, cid, eio))) {
180 		printf("error initializing %s parser at %#jx: %d\n", cls->name,
181 		    (uintmax_t)cid->enum_addr, error);
182 
183 		kobj_delete((kobj_t)erom, M_BHND);
184 		return (NULL);
185 	}
186 
187 	return (erom);
188 }
189 
190 /**
191  * Perform static initialization of a device enumeration table parser.
192  *
193  * This may be used to initialize a caller-allocated erom instance state
194  * during early boot, prior to malloc availability.
195  *
196  * @param cls		The parser class for which an instance will be
197  *			allocated.
198  * @param erom		The erom parser instance to initialize.
199  * @param esize		The total available number of bytes allocated for
200  *			@p erom. If this is less than is required by @p cls,
201  *			ENOMEM will be returned.
202  * @param cid		The device's chip identifier.
203  * @param eio		The bus I/O callbacks to use when reading the device
204  *			enumeration table.
205  *
206  * @retval 0		success
207  * @retval ENOMEM	if @p esize is smaller than required by @p cls.
208  * @retval non-zero	if an error occurs initializing the EROM parser,
209  *			a regular unix error code will be returned.
210  */
211 int
bhnd_erom_init_static(bhnd_erom_class_t * cls,bhnd_erom_t * erom,size_t esize,const struct bhnd_chipid * cid,struct bhnd_erom_io * eio)212 bhnd_erom_init_static(bhnd_erom_class_t *cls, bhnd_erom_t *erom, size_t esize,
213     const struct bhnd_chipid *cid, struct bhnd_erom_io *eio)
214 {
215 	kobj_class_t	kcls;
216 
217 	kcls = (kobj_class_t)cls;
218 
219 	/* Verify allocation size */
220 	if (kcls->size > esize)
221 		return (ENOMEM);
222 
223 	/* Perform instance initialization */
224 	kobj_init_static((kobj_t)erom, kcls);
225 	return (BHND_EROM_INIT(erom, cid, eio));
226 }
227 
228 /**
229  * Release any resources held by a @p erom parser previously
230  * initialized via bhnd_erom_init_static().
231  *
232  * @param	erom	An erom parser instance previously initialized via
233  *			bhnd_erom_init_static().
234  */
235 void
bhnd_erom_fini_static(bhnd_erom_t * erom)236 bhnd_erom_fini_static(bhnd_erom_t *erom)
237 {
238 	return (BHND_EROM_FINI(erom));
239 }
240 
241 /**
242  * Release all resources held by a @p erom parser previously
243  * allocated via bhnd_erom_alloc().
244  *
245  * @param	erom	An erom parser instance previously allocated via
246  *			bhnd_erom_alloc().
247  */
248 void
bhnd_erom_free(bhnd_erom_t * erom)249 bhnd_erom_free(bhnd_erom_t *erom)
250 {
251 	BHND_EROM_FINI(erom);
252 	kobj_delete((kobj_t)erom, M_BHND);
253 }
254 
255 /**
256  * Read the chip identification registers mapped by @p eio, popuating @p cid
257  * with the parsed result
258  *
259  * @param	eio		A bus I/O instance, configured with a mapping
260  *				of the ChipCommon core.
261  * @param[out]	cid		On success, the parsed chip identification.
262  *
263  * @warning
264  * On early siba(4) devices, the ChipCommon core does not provide
265  * a valid CHIPC_ID_NUMCORE field. On these ChipCommon revisions
266  * (see CHIPC_NCORES_MIN_HWREV()), this function will parse and return
267  * an invalid `ncores` value.
268  */
269 int
bhnd_erom_read_chipid(struct bhnd_erom_io * eio,struct bhnd_chipid * cid)270 bhnd_erom_read_chipid(struct bhnd_erom_io *eio, struct bhnd_chipid *cid)
271 {
272 	bhnd_addr_t	cc_addr;
273 	bhnd_size_t	cc_size;
274 	uint32_t	idreg, cc_caps;
275 	int		error;
276 
277 	/* Fetch ChipCommon address */
278 	if ((error = bhnd_erom_io_tell(eio, &cc_addr, &cc_size)))
279 		return (error);
280 
281 	/* Read chip identifier */
282 	idreg = bhnd_erom_io_read(eio, CHIPC_ID, 4);
283 
284 	/* Extract the basic chip info */
285 	cid->chip_id = CHIPC_GET_BITS(idreg, CHIPC_ID_CHIP);
286 	cid->chip_pkg = CHIPC_GET_BITS(idreg, CHIPC_ID_PKG);
287 	cid->chip_rev = CHIPC_GET_BITS(idreg, CHIPC_ID_REV);
288 	cid->chip_type = CHIPC_GET_BITS(idreg, CHIPC_ID_BUS);
289 	cid->ncores = CHIPC_GET_BITS(idreg, CHIPC_ID_NUMCORE);
290 
291 	/* Populate EROM address */
292 	if (BHND_CHIPTYPE_HAS_EROM(cid->chip_type)) {
293 		cid->enum_addr = bhnd_erom_io_read(eio, CHIPC_EROMPTR, 4);
294 	} else {
295 		cid->enum_addr = cc_addr;
296 	}
297 
298 	/* Populate capability flags */
299 	cc_caps = bhnd_erom_io_read(eio, CHIPC_CAPABILITIES, 4);
300 	cid->chip_caps = 0x0;
301 
302 	if (cc_caps & CHIPC_CAP_BKPLN64)
303 		cid->chip_caps |= BHND_CAP_BP64;
304 
305 	if (cc_caps & CHIPC_CAP_PMU)
306 		cid->chip_caps |= BHND_CAP_PMU;
307 
308 	return (0);
309 }
310 
311 /**
312  * Attempt to map @p size bytes at @p addr, replacing any existing
313  * @p eio mapping.
314  *
315  * @param eio	I/O instance state.
316  * @param addr	The address to be mapped.
317  * @param size	The number of bytes to be mapped at @p addr.
318  *
319  * @retval 0		success
320  * @retval non-zero	if mapping @p addr otherwise fails, a regular
321  *			unix error code should be returned.
322  */
323 int
bhnd_erom_io_map(struct bhnd_erom_io * eio,bhnd_addr_t addr,bhnd_size_t size)324 bhnd_erom_io_map(struct bhnd_erom_io *eio, bhnd_addr_t addr, bhnd_size_t size)
325 {
326 	return (eio->map(eio, addr, size));
327 }
328 
329 /**
330  * Return the address range mapped by @p eio, if any.
331  *
332  * @param	eio	I/O instance state.
333  * @param[out]	addr	The address mapped by @p eio.
334  * @param[out]	size	The number of bytes mapped at @p addr.
335  *
336  * @retval	0	success
337  * @retval	ENXIO	if @p eio has no mapping.
338  */
339 int
bhnd_erom_io_tell(struct bhnd_erom_io * eio,bhnd_addr_t * addr,bhnd_size_t * size)340 bhnd_erom_io_tell(struct bhnd_erom_io *eio, bhnd_addr_t *addr,
341     bhnd_size_t *size)
342 {
343 	return (eio->tell(eio, addr, size));
344 }
345 
346 /**
347  * Read a 1, 2, or 4 byte data item from @p eio, at the given @p offset
348  * relative to @p eio's current mapping.
349  *
350  * @param eio		erom I/O callbacks
351  * @param offset	read offset.
352  * @param width		item width (1, 2, or 4 bytes).
353  */
354 uint32_t
bhnd_erom_io_read(struct bhnd_erom_io * eio,bhnd_size_t offset,u_int width)355 bhnd_erom_io_read(struct bhnd_erom_io *eio, bhnd_size_t offset, u_int width)
356 {
357 	return (eio->read(eio, offset, width));
358 }
359 
360 /**
361  * Free all resources held by @p eio.
362  */
363 void
bhnd_erom_io_fini(struct bhnd_erom_io * eio)364 bhnd_erom_io_fini(struct bhnd_erom_io *eio)
365 {
366 	if (eio->fini != NULL)
367 		return (eio->fini(eio));
368 }
369 
370 /**
371  * Allocate, initialize, and return a new I/O instance that will perform
372  * mapping by allocating SYS_RES_MEMORY resources from @p dev using @p rid.
373  *
374  * @param dev	The device to pass to bhnd_alloc_resource() and
375  *		bhnd_release_resource() functions.
376  * @param rid	The resource ID to be used when allocating memory resources.
377  */
378 struct bhnd_erom_io *
bhnd_erom_iores_new(device_t dev,int rid)379 bhnd_erom_iores_new(device_t dev, int rid)
380 {
381 	struct bhnd_erom_iores	*iores;
382 
383 	iores = malloc(sizeof(*iores), M_BHND, M_WAITOK | M_ZERO);
384 	iores->eio.map = bhnd_erom_iores_map;
385 	iores->eio.tell = bhnd_erom_iores_tell;
386 	iores->eio.read = bhnd_erom_iores_read;
387 	iores->eio.fini = bhnd_erom_iores_fini;
388 
389 	iores->owner = dev;
390 	iores->owner_rid = rid;
391 	iores->mapped = NULL;
392 
393 	return (&iores->eio);
394 }
395 
396 static int
bhnd_erom_iores_map(struct bhnd_erom_io * eio,bhnd_addr_t addr,bhnd_size_t size)397 bhnd_erom_iores_map(struct bhnd_erom_io *eio, bhnd_addr_t addr,
398     bhnd_size_t size)
399 {
400 	struct bhnd_erom_iores *iores;
401 
402 	iores = (struct bhnd_erom_iores *)eio;
403 
404 	/* Sanity check the addr/size */
405 	if (size == 0)
406 		return (EINVAL);
407 
408 	if (BHND_ADDR_MAX - size < addr)
409 		return (EINVAL);	/* would overflow */
410 
411 	/* Check for an existing mapping */
412 	if (iores->mapped) {
413 		/* If already mapped, nothing else to do */
414 		if (rman_get_start(iores->mapped->res) == addr &&
415 		    rman_get_size(iores->mapped->res) == size)
416 		{
417 			return (0);
418 		}
419 
420 		/* Otherwise, we need to drop the existing mapping */
421 		bhnd_release_resource(iores->owner, iores->mapped);
422 		iores->mapped = NULL;
423 	}
424 
425 	/* Try to allocate the new mapping */
426 	iores->mapped = bhnd_alloc_resource(iores->owner, SYS_RES_MEMORY,
427 	    iores->owner_rid, addr, addr+size-1, size,
428 	    RF_ACTIVE|RF_SHAREABLE);
429 	if (iores->mapped == NULL) {
430 		return (ENXIO);
431 	}
432 
433 	return (0);
434 }
435 
436 static int
bhnd_erom_iores_tell(struct bhnd_erom_io * eio,bhnd_addr_t * addr,bhnd_size_t * size)437 bhnd_erom_iores_tell(struct bhnd_erom_io *eio, bhnd_addr_t *addr,
438     bhnd_size_t *size)
439 {
440 	struct bhnd_erom_iores *iores = (struct bhnd_erom_iores *)eio;
441 
442 	if (iores->mapped == NULL)
443 		return (ENXIO);
444 
445 	*addr = rman_get_start(iores->mapped->res);
446 	*size = rman_get_size(iores->mapped->res);
447 
448 	return (0);
449 }
450 
451 static uint32_t
bhnd_erom_iores_read(struct bhnd_erom_io * eio,bhnd_size_t offset,u_int width)452 bhnd_erom_iores_read(struct bhnd_erom_io *eio, bhnd_size_t offset, u_int width)
453 {
454 	struct bhnd_erom_iores *iores = (struct bhnd_erom_iores *)eio;
455 
456 	if (iores->mapped == NULL)
457 		panic("read with invalid mapping");
458 
459 	switch (width) {
460 	case 1:
461 		return (bhnd_bus_read_1(iores->mapped, offset));
462 	case 2:
463 		return (bhnd_bus_read_2(iores->mapped, offset));
464 	case 4:
465 		return (bhnd_bus_read_4(iores->mapped, offset));
466 	default:
467 		panic("invalid width %u", width);
468 	}
469 }
470 
471 static void
bhnd_erom_iores_fini(struct bhnd_erom_io * eio)472 bhnd_erom_iores_fini(struct bhnd_erom_io *eio)
473 {
474 	struct bhnd_erom_iores *iores = (struct bhnd_erom_iores *)eio;
475 
476 	/* Release any mapping */
477 	if (iores->mapped) {
478 		bhnd_release_resource(iores->owner, iores->mapped);
479 		iores->mapped = NULL;
480 	}
481 
482 	free(eio, M_BHND);
483 }
484 
485 /**
486  * Initialize an I/O instance that will perform mapping directly from the
487  * given bus space tag and handle.
488  *
489  * @param iobus	The I/O instance to be initialized.
490  * @param addr	The base address mapped by @p bsh.
491  * @param size	The total size mapped by @p bsh.
492  * @param bst	Bus space tag for @p bsh.
493  * @param bsh	Bus space handle mapping the full bus enumeration space.
494  *
495  * @retval 0		success
496  * @retval non-zero	if initializing @p iobus otherwise fails, a regular
497  *			unix error code will be returned.
498  */
499 int
bhnd_erom_iobus_init(struct bhnd_erom_iobus * iobus,bhnd_addr_t addr,bhnd_size_t size,bus_space_tag_t bst,bus_space_handle_t bsh)500 bhnd_erom_iobus_init(struct bhnd_erom_iobus *iobus, bhnd_addr_t addr,
501     bhnd_size_t size, bus_space_tag_t bst, bus_space_handle_t bsh)
502 {
503 	iobus->eio.map = bhnd_erom_iobus_map;
504 	iobus->eio.tell = bhnd_erom_iobus_tell;
505 	iobus->eio.read = bhnd_erom_iobus_read;
506 	iobus->eio.fini = NULL;
507 
508 	iobus->addr = addr;
509 	iobus->size = size;
510 	iobus->bst = bst;
511 	iobus->bsh = bsh;
512 	iobus->mapped = false;
513 
514 	return (0);
515 }
516 
517 static int
bhnd_erom_iobus_map(struct bhnd_erom_io * eio,bhnd_addr_t addr,bhnd_size_t size)518 bhnd_erom_iobus_map(struct bhnd_erom_io *eio, bhnd_addr_t addr,
519     bhnd_size_t size)
520 {
521 	struct bhnd_erom_iobus *iobus = (struct bhnd_erom_iobus *)eio;
522 
523 	/* Sanity check the addr/size */
524 	if (size == 0)
525 		return (EINVAL);
526 
527 	/* addr+size must not overflow */
528 	if (BHND_ADDR_MAX - size < addr)
529 		return (EINVAL);
530 
531 	/* addr/size must fit within our bus tag's mapping */
532 	if (addr < iobus->addr || size > iobus->size)
533 		return (ENXIO);
534 
535 	if (iobus->size - (addr - iobus->addr) < size)
536 		return (ENXIO);
537 
538 	/* The new addr offset and size must be representible as a bus_size_t */
539 	if ((addr - iobus->addr) > BUS_SPACE_MAXSIZE)
540 		return (ENXIO);
541 
542 	if (size > BUS_SPACE_MAXSIZE)
543 		return (ENXIO);
544 
545 	iobus->offset = addr - iobus->addr;
546 	iobus->limit = size;
547 	iobus->mapped = true;
548 
549 	return (0);
550 }
551 
552 static int
bhnd_erom_iobus_tell(struct bhnd_erom_io * eio,bhnd_addr_t * addr,bhnd_size_t * size)553 bhnd_erom_iobus_tell(struct bhnd_erom_io *eio, bhnd_addr_t *addr,
554     bhnd_size_t *size)
555 {
556 	struct bhnd_erom_iobus *iobus = (struct bhnd_erom_iobus *)eio;
557 
558 	if (!iobus->mapped)
559 		return (ENXIO);
560 
561 	*addr = iobus->addr + iobus->offset;
562 	*size = iobus->limit;
563 
564 	return (0);
565 }
566 
567 static uint32_t
bhnd_erom_iobus_read(struct bhnd_erom_io * eio,bhnd_size_t offset,u_int width)568 bhnd_erom_iobus_read(struct bhnd_erom_io *eio, bhnd_size_t offset, u_int width)
569 {
570 	struct bhnd_erom_iobus *iobus = (struct bhnd_erom_iobus *)eio;
571 
572 	if (!iobus->mapped)
573 		panic("no active mapping");
574 
575 	if (iobus->limit < width || iobus->limit - width < offset)
576 		panic("invalid offset %#jx", offset);
577 
578 	switch (width) {
579 	case 1:
580 		return (bus_space_read_1(iobus->bst, iobus->bsh,
581 		    iobus->offset + offset));
582 	case 2:
583 		return (bus_space_read_2(iobus->bst, iobus->bsh,
584 		    iobus->offset + offset));
585 	case 4:
586 		return (bus_space_read_4(iobus->bst, iobus->bsh,
587 		    iobus->offset + offset));
588 	default:
589 		panic("invalid width %u", width);
590 	}
591 }
592