xref: /titanic_41/usr/src/uts/i86pc/io/pci/pci_tools.c (revision 70025d765b044c6d8594bb965a2247a61e991a99)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/mkdev.h>
31 #include <sys/stat.h>
32 #include <sys/sunddi.h>
33 #include <vm/seg_kmem.h>
34 #include <sys/machparam.h>
35 #include <sys/ontrap.h>
36 #include <sys/pcie.h>
37 #include <sys/hotplug/pci/pcihp.h>
38 #include <sys/pci_cfgspace.h>
39 #include <sys/pci_tools.h>
40 #include "pci_tools_ext.h"
41 #include "pci_var.h"
42 #include <sys/promif.h>
43 
44 #define	PCIEX_BDF_OFFSET_DELTA	4
45 #define	PCIEX_REG_FUNC_SHIFT	(PCI_REG_FUNC_SHIFT + PCIEX_BDF_OFFSET_DELTA)
46 #define	PCIEX_REG_DEV_SHIFT	(PCI_REG_DEV_SHIFT + PCIEX_BDF_OFFSET_DELTA)
47 #define	PCIEX_REG_BUS_SHIFT	(PCI_REG_BUS_SHIFT + PCIEX_BDF_OFFSET_DELTA)
48 
49 #define	SUCCESS	0
50 
51 int pcitool_debug = 0;
52 
53 /*
54  * Offsets of BARS in config space.  First entry of 0 means config space.
55  * Entries here correlate to pcitool_bars_t enumerated type.
56  */
57 static uint8_t pci_bars[] = {
58 	0x0,
59 	PCI_CONF_BASE0,
60 	PCI_CONF_BASE1,
61 	PCI_CONF_BASE2,
62 	PCI_CONF_BASE3,
63 	PCI_CONF_BASE4,
64 	PCI_CONF_BASE5,
65 	PCI_CONF_ROM
66 };
67 
68 /* Max offset allowed into config space for a particular device. */
69 static uint64_t max_cfg_size = PCI_CONF_HDR_SIZE;
70 
71 static uint64_t pcitool_swap_endian(uint64_t data, int size);
72 static int pcitool_pciex_cfg_access(dev_info_t *dip, pcitool_reg_t *prg,
73     boolean_t write_flag);
74 static int pcitool_cfg_access(dev_info_t *dip, pcitool_reg_t *prg,
75     boolean_t write_flag);
76 static int pcitool_io_access(dev_info_t *dip, pcitool_reg_t *prg,
77     boolean_t write_flag);
78 static int pcitool_mem_access(dev_info_t *dip, pcitool_reg_t *prg,
79     uint64_t virt_addr, boolean_t write_flag);
80 static uint64_t pcitool_map(uint64_t phys_addr, size_t size, size_t *num_pages);
81 static void pcitool_unmap(uint64_t virt_addr, size_t num_pages);
82 
83 int
84 pcitool_init(dev_info_t *dip, boolean_t is_pciex)
85 {
86 	int instance = ddi_get_instance(dip);
87 
88 	/* Create pcitool nodes for register access and interrupt routing. */
89 
90 	if (ddi_create_minor_node(dip, PCI_MINOR_REG, S_IFCHR,
91 	    PCIHP_AP_MINOR_NUM(instance, PCI_TOOL_REG_MINOR_NUM),
92 	    DDI_NT_REGACC, 0) != DDI_SUCCESS) {
93 		return (DDI_FAILURE);
94 	}
95 
96 	if (ddi_create_minor_node(dip, PCI_MINOR_INTR, S_IFCHR,
97 	    PCIHP_AP_MINOR_NUM(instance, PCI_TOOL_INTR_MINOR_NUM),
98 	    DDI_NT_INTRCTL, 0) != DDI_SUCCESS) {
99 		ddi_remove_minor_node(dip, PCI_MINOR_REG);
100 		return (DDI_FAILURE);
101 	}
102 
103 	if (is_pciex)
104 		max_cfg_size = PCIE_CONF_HDR_SIZE;
105 
106 	return (DDI_SUCCESS);
107 }
108 
109 void
110 pcitool_uninit(dev_info_t *dip)
111 {
112 	ddi_remove_minor_node(dip, PCI_MINOR_INTR);
113 	ddi_remove_minor_node(dip, PCI_MINOR_REG);
114 }
115 
116 
117 /*
118  * A note about ontrap handling:
119  *
120  * X86 systems on which this module was tested return FFs instead of bus errors
121  * when accessing devices with invalid addresses.  Ontrap handling, which
122  * gracefully handles kernel bus errors, is installed anyway, in case future
123  * X86 platforms require it.
124  */
125 
126 /*
127  * Main function for handling interrupt CPU binding requests and queries.
128  * Need to implement later
129  */
130 /*ARGSUSED*/
131 int
132 pcitool_intr_admn(dev_info_t *dip, void *arg, int cmd, int mode)
133 {
134 	return (ENOTSUP);
135 }
136 
137 
138 /*
139  * Perform register accesses on the nexus device itself.
140  * No explicit PCI nexus device for X86, so not applicable.
141  */
142 /*ARGSUSED*/
143 int
144 pcitool_bus_reg_ops(dev_info_t *dip, void *arg, int cmd, int mode)
145 {
146 	return (ENOTSUP);
147 }
148 
149 /* Swap endianness. */
150 static uint64_t
151 pcitool_swap_endian(uint64_t data, int size)
152 {
153 	typedef union {
154 		uint64_t data64;
155 		uint8_t data8[8];
156 	} data_split_t;
157 
158 	data_split_t orig_data;
159 	data_split_t returned_data;
160 	int i;
161 
162 	orig_data.data64 = data;
163 	returned_data.data64 = 0;
164 
165 	for (i = 0; i < size; i++) {
166 		returned_data.data8[i] = orig_data.data8[size - 1 - i];
167 	}
168 
169 	return (returned_data.data64);
170 }
171 
172 
173 /*
174  * Access device.  prg is modified.
175  *
176  * Extended config space is available only through memory-mapped access.
177  * Standard config space on pci express devices is available either way,
178  * so do it memory-mapped here too, for simplicity.
179  */
180 /*ARGSUSED*/
181 static int
182 pcitool_pciex_cfg_access(dev_info_t *dip, pcitool_reg_t *prg,
183     boolean_t write_flag)
184 {
185 	int rval = SUCCESS;
186 	uint64_t virt_addr;
187 	size_t	num_virt_pages;
188 
189 	prg->status = PCITOOL_SUCCESS;
190 
191 	prg->phys_addr = ddi_prop_get_int64(DDI_DEV_T_ANY, dip, 0,
192 	    "ecfga-base-address", 0);
193 	if (prg->phys_addr == 0) {
194 		prg->status = PCITOOL_IO_ERROR;
195 		return (EIO);
196 	}
197 
198 	prg->phys_addr += prg->offset +
199 	    ((prg->bus_no << PCIEX_REG_BUS_SHIFT) |
200 	    (prg->dev_no << PCIEX_REG_DEV_SHIFT) |
201 	    (prg->func_no << PCIEX_REG_FUNC_SHIFT));
202 
203 	virt_addr = pcitool_map(prg->phys_addr,
204 	    PCITOOL_ACC_ATTR_SIZE(prg->acc_attr), &num_virt_pages);
205 	if (virt_addr == NULL) {
206 		prg->status = PCITOOL_IO_ERROR;
207 		return (EIO);
208 	}
209 
210 	rval = pcitool_mem_access(dip, prg, virt_addr, write_flag);
211 	pcitool_unmap(virt_addr, num_virt_pages);
212 	return (rval);
213 }
214 
215 /* Access device.  prg is modified. */
216 /*ARGSUSED*/
217 static int
218 pcitool_cfg_access(dev_info_t *dip, pcitool_reg_t *prg, boolean_t write_flag)
219 {
220 	int size = PCITOOL_ACC_ATTR_SIZE(prg->acc_attr);
221 	boolean_t big_endian = PCITOOL_ACC_IS_BIG_ENDIAN(prg->acc_attr);
222 	int rval = SUCCESS;
223 	uint64_t local_data;
224 
225 	/*
226 	 * NOTE: there is no way to verify whether or not the address is valid.
227 	 * The put functions return void and the get functions return ff on
228 	 * error.
229 	 */
230 	prg->status = PCITOOL_SUCCESS;
231 
232 	if (write_flag) {
233 
234 		if (big_endian) {
235 			local_data = pcitool_swap_endian(prg->data, size);
236 		} else {
237 			local_data = prg->data;
238 		}
239 
240 		switch (size) {
241 		case 1:
242 			(*pci_putb_func)(prg->bus_no, prg->dev_no,
243 			    prg->func_no, prg->offset, local_data);
244 			break;
245 		case 2:
246 			(*pci_putw_func)(prg->bus_no, prg->dev_no,
247 			    prg->func_no, prg->offset, local_data);
248 			break;
249 		case 4:
250 			(*pci_putl_func)(prg->bus_no, prg->dev_no,
251 			    prg->func_no, prg->offset, local_data);
252 			break;
253 		default:
254 			rval = ENOTSUP;
255 			prg->status = PCITOOL_INVALID_SIZE;
256 			break;
257 		}
258 	} else {
259 		switch (size) {
260 		case 1:
261 			local_data = (*pci_getb_func)(prg->bus_no, prg->dev_no,
262 			    prg->func_no, prg->offset);
263 			break;
264 		case 2:
265 			local_data = (*pci_getw_func)(prg->bus_no, prg->dev_no,
266 			    prg->func_no, prg->offset);
267 			break;
268 		case 4:
269 			local_data = (*pci_getl_func)(prg->bus_no, prg->dev_no,
270 			    prg->func_no, prg->offset);
271 			break;
272 		default:
273 			rval = ENOTSUP;
274 			prg->status = PCITOOL_INVALID_SIZE;
275 			break;
276 		}
277 
278 		if (rval == SUCCESS) {
279 			if (big_endian) {
280 				prg->data =
281 				    pcitool_swap_endian(local_data, size);
282 			} else {
283 				prg->data = local_data;
284 			}
285 		}
286 	}
287 	prg->phys_addr = 0;	/* Config space is not memory mapped on X86. */
288 	return (rval);
289 }
290 
291 
292 /*ARGSUSED*/
293 static int
294 pcitool_io_access(dev_info_t *dip, pcitool_reg_t *prg, boolean_t write_flag)
295 {
296 	int port = (int)prg->phys_addr;
297 	size_t size = PCITOOL_ACC_ATTR_SIZE(prg->acc_attr);
298 	boolean_t big_endian = PCITOOL_ACC_IS_BIG_ENDIAN(prg->acc_attr);
299 	int rval = SUCCESS;
300 	on_trap_data_t otd;
301 	uint64_t local_data;
302 
303 
304 	/*
305 	 * on_trap works like setjmp.
306 	 *
307 	 * A non-zero return here means on_trap has returned from an error.
308 	 *
309 	 * A zero return here means that on_trap has just returned from setup.
310 	 */
311 	if (on_trap(&otd, OT_DATA_ACCESS)) {
312 		no_trap();
313 		if (pcitool_debug)
314 			prom_printf(
315 			    "pcitool_mem_access: on_trap caught an error...\n");
316 		prg->status = PCITOOL_INVALID_ADDRESS;
317 		return (EFAULT);
318 	}
319 
320 	if (write_flag) {
321 
322 		if (big_endian) {
323 			local_data = pcitool_swap_endian(prg->data, size);
324 		} else {
325 			local_data = prg->data;
326 		}
327 
328 		if (pcitool_debug)
329 			prom_printf("Writing %ld byte(s) to port 0x%x\n",
330 			    size, port);
331 
332 		switch (size) {
333 		case 1:
334 			outb(port, (uint8_t)local_data);
335 			break;
336 		case 2:
337 			outw(port, (uint16_t)local_data);
338 			break;
339 		case 4:
340 			outl(port, (uint32_t)local_data);
341 			break;
342 		default:
343 			rval = ENOTSUP;
344 			prg->status = PCITOOL_INVALID_SIZE;
345 			break;
346 		}
347 	} else {
348 		if (pcitool_debug)
349 			prom_printf("Reading %ld byte(s) from port 0x%x\n",
350 			    size, port);
351 
352 		switch (size) {
353 		case 1:
354 			local_data = inb(port);
355 			break;
356 		case 2:
357 			local_data = inw(port);
358 			break;
359 		case 4:
360 			local_data = inl(port);
361 			break;
362 		default:
363 			rval = ENOTSUP;
364 			prg->status = PCITOOL_INVALID_SIZE;
365 			break;
366 		}
367 
368 		if (rval == SUCCESS) {
369 			if (big_endian) {
370 				prg->data =
371 				    pcitool_swap_endian(local_data, size);
372 			} else {
373 				prg->data = local_data;
374 			}
375 		}
376 	}
377 
378 	no_trap();
379 	return (rval);
380 }
381 
382 /*ARGSUSED*/
383 static int
384 pcitool_mem_access(dev_info_t *dip, pcitool_reg_t *prg, uint64_t virt_addr,
385 	boolean_t write_flag)
386 {
387 	size_t size = PCITOOL_ACC_ATTR_SIZE(prg->acc_attr);
388 	boolean_t big_endian = PCITOOL_ACC_IS_BIG_ENDIAN(prg->acc_attr);
389 	int rval = DDI_SUCCESS;
390 	on_trap_data_t otd;
391 	uint64_t local_data;
392 
393 	/*
394 	 * on_trap works like setjmp.
395 	 *
396 	 * A non-zero return here means on_trap has returned from an error.
397 	 *
398 	 * A zero return here means that on_trap has just returned from setup.
399 	 */
400 	if (on_trap(&otd, OT_DATA_ACCESS)) {
401 		no_trap();
402 		if (pcitool_debug)
403 			prom_printf(
404 			    "pcitool_mem_access: on_trap caught an error...\n");
405 		prg->status = PCITOOL_INVALID_ADDRESS;
406 		return (EFAULT);
407 	}
408 
409 	if (write_flag) {
410 
411 		if (big_endian) {
412 			local_data = pcitool_swap_endian(prg->data, size);
413 		} else {
414 			local_data = prg->data;
415 		}
416 
417 		switch (size) {
418 		case 1:
419 			*((uint8_t *)(uintptr_t)virt_addr) = local_data;
420 			break;
421 		case 2:
422 			*((uint16_t *)(uintptr_t)virt_addr) = local_data;
423 			break;
424 		case 4:
425 			*((uint32_t *)(uintptr_t)virt_addr) = local_data;
426 			break;
427 		case 8:
428 			*((uint64_t *)(uintptr_t)virt_addr) = local_data;
429 			break;
430 		default:
431 			rval = ENOTSUP;
432 			prg->status = PCITOOL_INVALID_SIZE;
433 			break;
434 		}
435 	} else {
436 		switch (size) {
437 		case 1:
438 			local_data = *((uint8_t *)(uintptr_t)virt_addr);
439 			break;
440 		case 2:
441 			local_data = *((uint16_t *)(uintptr_t)virt_addr);
442 			break;
443 		case 4:
444 			local_data = *((uint32_t *)(uintptr_t)virt_addr);
445 			break;
446 		case 8:
447 			local_data = *((uint64_t *)(uintptr_t)virt_addr);
448 			break;
449 		default:
450 			rval = ENOTSUP;
451 			prg->status = PCITOOL_INVALID_SIZE;
452 			break;
453 		}
454 
455 		if (rval == SUCCESS) {
456 			if (big_endian) {
457 				prg->data =
458 				    pcitool_swap_endian(local_data, size);
459 			} else {
460 				prg->data = local_data;
461 			}
462 		}
463 	}
464 
465 	no_trap();
466 	return (rval);
467 }
468 
469 /*
470  * Map up to 2 pages which contain the address we want to access.
471  *
472  * Mapping should span no more than 8 bytes.  With X86 it is possible for an
473  * 8 byte value to start on a 4 byte boundary, so it can cross a page boundary.
474  * We'll never have to map more than two pages.
475  */
476 
477 static uint64_t
478 pcitool_map(uint64_t phys_addr, size_t size, size_t *num_pages)
479 {
480 
481 	uint64_t page_base = phys_addr & ~MMU_PAGEOFFSET;
482 	uint64_t offset = phys_addr & MMU_PAGEOFFSET;
483 	void *virt_base;
484 	uint64_t returned_addr;
485 
486 	if (pcitool_debug)
487 		prom_printf("pcitool_map: Called with PA:0x%p\n",
488 		    (uint8_t *)(uintptr_t)phys_addr);
489 
490 	*num_pages = 1;
491 
492 	/* Desired mapping would span more than two pages. */
493 	if ((offset + size) > (MMU_PAGESIZE * 2)) {
494 		if (pcitool_debug)
495 			prom_printf("boundary violation: "
496 			    "offset:0x%" PRIx64 ", size:%ld, pagesize:0x%lx\n",
497 			    offset, (uintptr_t)size, (uintptr_t)MMU_PAGESIZE);
498 		return (NULL);
499 
500 	} else if ((offset + size) > MMU_PAGESIZE) {
501 		(*num_pages)++;
502 	}
503 
504 	/* Get page(s) of virtual space. */
505 	virt_base = vmem_alloc(heap_arena, ptob(*num_pages), VM_NOSLEEP);
506 	if (virt_base == NULL) {
507 		if (pcitool_debug)
508 			prom_printf("Couldn't get virtual base address.\n");
509 		return (NULL);
510 	}
511 
512 	if (pcitool_debug)
513 		prom_printf("Got base virtual address:0x%p\n", virt_base);
514 
515 	/* Now map the allocated virtual space to the physical address. */
516 	hat_devload(kas.a_hat, virt_base, mmu_ptob(*num_pages),
517 	    mmu_btop(page_base), PROT_READ | PROT_WRITE | HAT_STRICTORDER,
518 	    HAT_LOAD_LOCK);
519 
520 	returned_addr = ((uintptr_t)(virt_base)) + offset;
521 
522 	if (pcitool_debug)
523 		prom_printf("pcitool_map: returning VA:0x%p\n",
524 		    (void *)(uintptr_t)returned_addr);
525 
526 	return (returned_addr);
527 }
528 
529 /* Unmap the mapped page(s). */
530 static void
531 pcitool_unmap(uint64_t virt_addr, size_t num_pages)
532 {
533 	void *base_virt_addr = (void *)(uintptr_t)(virt_addr & ~MMU_PAGEOFFSET);
534 
535 	hat_unload(kas.a_hat, base_virt_addr, ptob(num_pages),
536 	    HAT_UNLOAD_UNLOCK);
537 	vmem_free(heap_arena, base_virt_addr, ptob(num_pages));
538 }
539 
540 
541 /* Perform register accesses on PCI leaf devices. */
542 int
543 pcitool_dev_reg_ops(dev_info_t *dip, void *arg, int cmd, int mode)
544 {
545 	boolean_t	write_flag = B_FALSE;
546 	int		rval = 0;
547 	pcitool_reg_t	prg;
548 	uint8_t		size;
549 
550 	uint64_t	base_addr;
551 	uint64_t	virt_addr;
552 	size_t		num_virt_pages;
553 
554 	switch (cmd) {
555 	case (PCITOOL_DEVICE_SET_REG):
556 		write_flag = B_TRUE;
557 
558 	/*FALLTHRU*/
559 	case (PCITOOL_DEVICE_GET_REG):
560 		if (pcitool_debug)
561 			prom_printf("pci_dev_reg_ops set/get reg\n");
562 		if (ddi_copyin(arg, &prg, sizeof (pcitool_reg_t), mode) !=
563 		    DDI_SUCCESS) {
564 			if (pcitool_debug)
565 				prom_printf("Error reading arguments\n");
566 			return (EFAULT);
567 		}
568 
569 		if (prg.barnum >= (sizeof (pci_bars) / sizeof (pci_bars[0]))) {
570 			prg.status = PCITOOL_OUT_OF_RANGE;
571 			rval = EINVAL;
572 			goto done_reg;
573 		}
574 
575 		if (pcitool_debug)
576 			prom_printf("raw bus:0x%x, dev:0x%x, func:0x%x\n",
577 			    prg.bus_no, prg.dev_no, prg.func_no);
578 		/* Validate address arguments of bus / dev / func */
579 		if (((prg.bus_no &
580 		    (PCI_REG_BUS_M >> PCI_REG_BUS_SHIFT)) !=
581 		    prg.bus_no) ||
582 		    ((prg.dev_no &
583 		    (PCI_REG_DEV_M >> PCI_REG_DEV_SHIFT)) !=
584 		    prg.dev_no) ||
585 		    ((prg.func_no &
586 		    (PCI_REG_FUNC_M >> PCI_REG_FUNC_SHIFT)) !=
587 		    prg.func_no)) {
588 			prg.status = PCITOOL_INVALID_ADDRESS;
589 			rval = EINVAL;
590 			goto done_reg;
591 		}
592 
593 		size = PCITOOL_ACC_ATTR_SIZE(prg.acc_attr);
594 
595 		/* Proper config space desired. */
596 		if (prg.barnum == 0) {
597 
598 			if (pcitool_debug)
599 				prom_printf(
600 				    "config access: offset:0x%" PRIx64 ", "
601 				    "phys_addr:0x%" PRIx64 "\n",
602 				    prg.offset, prg.phys_addr);
603 
604 			if (prg.offset >= max_cfg_size) {
605 				prg.status = PCITOOL_OUT_OF_RANGE;
606 				rval = EINVAL;
607 				goto done_reg;
608 			}
609 
610 			/* Access device.  prg is modified. */
611 			if (max_cfg_size == PCIE_CONF_HDR_SIZE)
612 				rval = pcitool_pciex_cfg_access(dip, &prg,
613 				    write_flag);
614 			else
615 				rval = pcitool_cfg_access(dip, &prg,
616 				    write_flag);
617 
618 			if (pcitool_debug)
619 				prom_printf(
620 				    "config access: data:0x%" PRIx64 "\n",
621 				    prg.data);
622 
623 		/* IO/ MEM/ MEM64 space. */
624 		} else {
625 
626 			pcitool_reg_t	prg2;
627 			bcopy(&prg, &prg2, sizeof (pcitool_reg_t));
628 
629 			/*
630 			 * Translate BAR number into offset of the BAR in
631 			 * the device's config space.
632 			 */
633 			prg2.offset = pci_bars[prg2.barnum];
634 			prg2.acc_attr =
635 			    PCITOOL_ACC_ATTR_SIZE_4 | PCITOOL_ACC_ATTR_ENDN_LTL;
636 
637 			if (pcitool_debug)
638 				prom_printf(
639 				    "barnum:%d, bar_offset:0x%" PRIx64 "\n",
640 				    prg2.barnum, prg2.offset);
641 			/*
642 			 * Get Bus Address Register (BAR) from config space.
643 			 * prg2.offset is the offset into config space of the
644 			 * BAR desired.  prg.status is modified on error.
645 			 */
646 			rval = pcitool_cfg_access(dip, &prg2, B_FALSE);
647 			if (rval != SUCCESS) {
648 				if (pcitool_debug)
649 					prom_printf("BAR access failed\n");
650 				prg.status = prg2.status;
651 				goto done_reg;
652 			}
653 			/*
654 			 * Reference proper PCI space based on the BAR.
655 			 * If 64 bit MEM space, need to load other half of the
656 			 * BAR first.
657 			 */
658 
659 			if (pcitool_debug)
660 				prom_printf("bar returned is 0x%" PRIx64 "\n",
661 				    prg2.data);
662 			if (!prg2.data) {
663 				if (pcitool_debug)
664 					prom_printf("BAR data == 0\n");
665 				rval = EINVAL;
666 				prg.status = PCITOOL_INVALID_ADDRESS;
667 				goto done_reg;
668 			}
669 			if (prg2.data == 0xffffffff) {
670 				if (pcitool_debug)
671 					prom_printf("BAR data == -1\n");
672 				rval = EINVAL;
673 				prg.status = PCITOOL_INVALID_ADDRESS;
674 				goto done_reg;
675 			}
676 
677 			/*
678 			 * BAR has bits saying this space is IO space, unless
679 			 * this is the ROM address register.
680 			 */
681 			if (((PCI_BASE_SPACE_M & prg2.data) ==
682 			    PCI_BASE_SPACE_IO) &&
683 			    (prg2.offset != PCI_CONF_ROM)) {
684 				if (pcitool_debug)
685 					prom_printf("IO space\n");
686 
687 				prg2.data &= PCI_BASE_IO_ADDR_M;
688 				prg.phys_addr = prg2.data + prg.offset;
689 
690 				rval = pcitool_io_access(dip, &prg, write_flag);
691 				if ((rval != SUCCESS) && (pcitool_debug))
692 					prom_printf("IO access failed\n");
693 
694 				goto done_reg;
695 
696 
697 			/*
698 			 * BAR has bits saying this space is 64 bit memory
699 			 * space, unless this is the ROM address register.
700 			 *
701 			 * The 64 bit address stored in two BAR cells is not
702 			 * necessarily aligned on an 8-byte boundary.
703 			 * Need to keep the first 4 bytes read,
704 			 * and do a separate read of the high 4 bytes.
705 			 */
706 
707 			} else if ((PCI_BASE_TYPE_ALL & prg2.data) &&
708 			    (prg2.offset != PCI_CONF_ROM)) {
709 
710 				uint32_t low_bytes =
711 				    (uint32_t)(prg2.data & ~PCI_BASE_TYPE_ALL);
712 
713 				/*
714 				 * Don't try to read the next 4 bytes
715 				 * past the end of BARs.
716 				 */
717 				if (prg2.offset >= PCI_CONF_BASE5) {
718 					prg.status = PCITOOL_OUT_OF_RANGE;
719 					rval = EIO;
720 					goto done_reg;
721 				}
722 
723 				/*
724 				 * Access device.
725 				 * prg2.status is modified on error.
726 				 */
727 				prg2.offset += 4;
728 				rval = pcitool_cfg_access(dip, &prg2, B_FALSE);
729 				if (rval != SUCCESS) {
730 					prg.status = prg2.status;
731 					goto done_reg;
732 				}
733 
734 				if (prg2.data == 0xffffffff) {
735 					prg.status = PCITOOL_INVALID_ADDRESS;
736 					prg.status = EFAULT;
737 					goto done_reg;
738 				}
739 
740 				prg2.data = (prg2.data << 32) + low_bytes;
741 				if (pcitool_debug)
742 					prom_printf(
743 					    "64 bit mem space.  "
744 					    "64-bit bar is 0x%" PRIx64 "\n",
745 					    prg2.data);
746 
747 			/* Mem32 space, including ROM */
748 			} else {
749 
750 				if (prg2.offset == PCI_CONF_ROM) {
751 					if (pcitool_debug)
752 						prom_printf(
753 						    "Additional ROM "
754 						    "checking\n");
755 					/* Can't write to ROM */
756 					if (write_flag) {
757 						prg.status = PCITOOL_ROM_WRITE;
758 						rval = EIO;
759 						goto done_reg;
760 
761 					/* ROM disabled for reading */
762 					} else if (!(prg2.data & 0x00000001)) {
763 						prg.status =
764 						    PCITOOL_ROM_DISABLED;
765 						rval = EIO;
766 						goto done_reg;
767 					}
768 				}
769 
770 				if (pcitool_debug)
771 					prom_printf("32 bit mem space\n");
772 			}
773 
774 			/* Common code for all IO/MEM range spaces. */
775 
776 			base_addr = prg2.data;
777 			if (pcitool_debug)
778 				prom_printf(
779 				    "addr portion of bar is 0x%" PRIx64 ", "
780 				    "base=0x%" PRIx64 ", "
781 				    "offset:0x%" PRIx64 "\n",
782 				    prg2.data, base_addr, prg.offset);
783 			/*
784 			 * Use offset provided by caller to index into
785 			 * desired space, then access.
786 			 * Note that prg.status is modified on error.
787 			 */
788 			prg.phys_addr = base_addr + prg.offset;
789 
790 			virt_addr = pcitool_map(prg.phys_addr, size,
791 			    &num_virt_pages);
792 			if (virt_addr == NULL) {
793 				prg.status = PCITOOL_IO_ERROR;
794 				rval = EIO;
795 				goto done_reg;
796 			}
797 
798 			rval = pcitool_mem_access(dip, &prg, virt_addr,
799 			    write_flag);
800 			pcitool_unmap(virt_addr, num_virt_pages);
801 		}
802 done_reg:
803 		if (ddi_copyout(&prg, arg, sizeof (pcitool_reg_t), mode) !=
804 		    DDI_SUCCESS) {
805 			if (pcitool_debug)
806 				prom_printf("Error returning arguments.\n");
807 			rval = EFAULT;
808 		}
809 		break;
810 	default:
811 		rval = ENOTTY;
812 		break;
813 	}
814 	return (rval);
815 }
816