aboutsummaryrefslogtreecommitdiff
path: root/sys/sys/bus_dma.h
blob: 28e80ba2b89aa94ada505e014de50ae53259a1ae (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
/*	$NetBSD: bus.h,v 1.12 1997/10/01 08:25:15 fvdl Exp $	*/

/*-
 * Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
 * NASA Ames Research Center.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the NetBSD
 *	Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright (c) 1996 Charles M. Hannum.  All rights reserved.
 * Copyright (c) 1996 Christopher G. Demetriou.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Christopher G. Demetriou
 *	for the NetBSD Project.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/* $Id: bus.h,v 1.4 1998/09/29 09:06:00 bde Exp $ */

#ifndef _I386_BUS_H_
#define _I386_BUS_H_

#include <machine/cpufunc.h>

/*
 * To remain compatible with NetBSD's interface, default to both memio and
 * pio when neither of them is defined.
 */ 
#if !defined(_I386_BUS_PIO_H_) && !defined(_I386_BUS_MEMIO_H_)
#define _I386_BUS_PIO_H_
#define _I386_BUS_MEMIO_H_
#endif

/*
 * Values for the i386 bus space tag, not to be used directly by MI code.
 */
#define	I386_BUS_SPACE_IO	0	/* space is i/o space */
#define I386_BUS_SPACE_MEM	1	/* space is mem space */

/*
 * Bus address and size types
 */
typedef u_int bus_addr_t;
typedef u_int bus_size_t;

#define BUS_SPACE_MAXSIZE_24BIT	0xFFFFFF
#define BUS_SPACE_MAXSIZE_32BIT 0xFFFFFFFF
#define BUS_SPACE_MAXSIZE	(64 * 1024) /* Maximum supported size */
#define BUS_SPACE_MAXADDR_24BIT	0xFFFFFF
#define BUS_SPACE_MAXADDR_32BIT 0xFFFFFFFF
#define BUS_SPACE_MAXADDR	0xFFFFFFFF

#define BUS_SPACE_UNRESTRICTED	(~0)

/*
 * Access methods for bus resources and address space.
 */
typedef	int bus_space_tag_t;
typedef	u_int bus_space_handle_t;

/*
 * Map a region of device bus space into CPU virtual address space.
 */

#define	BUS_SPACE_MAP_CACHEABLE		0x01
#define	BUS_SPACE_MAP_LINEAR		0x02

int	bus_space_map(bus_space_tag_t t, bus_addr_t addr, bus_size_t size,
		      int flags, bus_space_handle_t *bshp);

/*
 * Unmap a region of device bus space.
 */

void	bus_space_unmap(bus_space_tag_t t, bus_space_handle_t bsh,
			bus_size_t size);

/*
 * Get a new handle for a subregion of an already-mapped area of bus space.
 */

int	bus_space_subregion(bus_space_tag_t t, bus_space_handle_t bsh,
			    bus_size_t offset, bus_size_t size,
			    bus_space_handle_t *nbshp);

/*
 * Allocate a region of memory that is accessible to devices in bus space.
 */

int	bus_space_alloc(bus_space_tag_t t, bus_addr_t rstart,
			bus_addr_t rend, bus_size_t size, bus_size_t align,
			bus_size_t boundary, int flags, bus_addr_t *addrp,
			bus_space_handle_t *bshp);

/*
 * Free a region of bus space accessible memory.
 */

void	bus_space_free(bus_space_tag_t t, bus_space_handle_t bsh,
		       bus_size_t size);

#if defined(_I386_BUS_PIO_H_) || defined(_I386_BUS_MEMIO_H_)

/*
 * Read a 1, 2, 4, or 8 byte quantity from bus space
 * described by tag/handle/offset.
 */
static __inline u_int8_t bus_space_read_1(bus_space_tag_t tag,
					  bus_space_handle_t handle,
					  bus_size_t offset);

static __inline u_int16_t bus_space_read_2(bus_space_tag_t tag,
					   bus_space_handle_t handle,
					   bus_size_t offset);

static __inline u_int32_t bus_space_read_4(bus_space_tag_t tag,
					   bus_space_handle_t handle,
					   bus_size_t offset);

static __inline u_int8_t
bus_space_read_1(bus_space_tag_t tag, bus_space_handle_t handle,
		 bus_size_t offset)
{
#if defined (_I386_BUS_PIO_H_)
#if defined (_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		return (inb(handle + offset));
#endif
#if defined (_I386_BUS_MEMIO_H_)
	return (*(volatile u_int8_t *)(handle + offset));
#endif
}

static __inline u_int16_t
bus_space_read_2(bus_space_tag_t tag, bus_space_handle_t handle,
		 bus_size_t offset)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		return (inw(handle + offset));
#endif
#if defined(_I386_BUS_MEMIO_H_)
	return (*(volatile u_int16_t *)(handle + offset));
#endif
}

static __inline u_int32_t
bus_space_read_4(bus_space_tag_t tag, bus_space_handle_t handle,
		 bus_size_t offset)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		return (inl(handle + offset));
#endif
#if defined(_I386_BUS_MEMIO_H_)
	return (*(volatile u_int32_t *)(handle + offset));
#endif
}

#if 0	/* Cause a link error for bus_space_read_8 */
#define	bus_space_read_8(t, h, o)	!!! bus_space_read_8 unimplemented !!!
#endif

/*
 * Read `count' 1, 2, 4, or 8 byte quantities from bus space
 * described by tag/handle/offset and copy into buffer provided.
 */
static __inline void bus_space_read_multi_1(bus_space_tag_t tag,
					    bus_space_handle_t bsh,
					    bus_size_t offset, u_int8_t *addr,
					    size_t count);

static __inline void bus_space_read_multi_2(bus_space_tag_t tag,
					    bus_space_handle_t bsh,
					    bus_size_t offset, u_int16_t *addr,
					    size_t count);

static __inline void bus_space_read_multi_4(bus_space_tag_t tag,
					    bus_space_handle_t bsh,
					    bus_size_t offset, u_int32_t *addr,
					    size_t count);

static __inline void
bus_space_read_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
		       bus_size_t offset, u_int8_t *addr, size_t count)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		insb(bsh + offset, addr, count);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		int __x __asm__("%eax");
		__asm __volatile("				\n\
			cld					\n\
		1:	movb (%1),%%al				\n\
			stosb					\n\
			loop 1b"				:
		    "=&a" (__x)					:
		    "r" (bsh + offset), "D" (addr), "c" (count)	:
		    "%edi", "%ecx", "memory");
	}
#endif
}

static __inline void
bus_space_read_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
		       bus_size_t offset, u_int16_t *addr, size_t count)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		insw(bsh + offset, addr, count);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		int __x __asm__("%eax");
		__asm __volatile("				\n\
			cld					\n\
		1:	movw (%1),%%ax				\n\
			stosw					\n\
			loop 1b"				:
		    "=&a" (__x)					:
		    "r" (bsh + offset), "D" (addr), "c" (count)	:
		    "%edi", "%ecx", "memory");
	}
#endif
}

static __inline void
bus_space_read_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
		       bus_size_t offset, u_int32_t *addr, size_t count)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		insl(bsh + offset, addr, count);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		int __x __asm__("%eax");
		__asm __volatile("				\n\
			cld					\n\
		1:	movl (%1),%%eax				\n\
			stosl					\n\
			loop 1b"				:
		    "=&a" (__x)					:
		    "r" (bsh + offset), "D" (addr), "c" (count)	:
		    "%edi", "%ecx", "memory");
	}
#endif
}

#if 0	/* Cause a link error for bus_space_read_multi_8 */
#define	bus_space_read_multi_8	!!! bus_space_read_multi_8 unimplemented !!!
#endif

/*
 * Read `count' 1, 2, 4, or 8 byte quantities from bus space
 * described by tag/handle and starting at `offset' and copy into
 * buffer provided.
 */
static __inline void bus_space_read_region_1(bus_space_tag_t tag,
					     bus_space_handle_t bsh,
					     bus_size_t offset, u_int8_t *addr,
					     size_t count);

static __inline void bus_space_read_region_2(bus_space_tag_t tag,
					     bus_space_handle_t bsh,
					     bus_size_t offset, u_int16_t *addr,
					     size_t count);

static __inline void bus_space_read_region_4(bus_space_tag_t tag,
					     bus_space_handle_t bsh,
					     bus_size_t offset, u_int32_t *addr,
					     size_t count);


static __inline void
bus_space_read_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
			bus_size_t offset, u_int8_t *addr, size_t count)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
	{
		int __x __asm__("%eax");
		__asm __volatile("				\n\
			cld					\n\
		1:	inb %w1,%%al				\n\
			stosb					\n\
			incl %1					\n\
			loop 1b"				:
		    "=&a" (__x)					:
		    "d" (bsh + offset), "D" (addr), "c" (count)	:
		    "%edx", "%edi", "%ecx", "memory");
	}
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		__asm __volatile("				\n\
			cld					\n\
			repne					\n\
			movsb"					:
								:
		    "S" (bsh + offset), "D" (addr), "c" (count)	:
		    "%esi", "%edi", "%ecx", "memory");
	}
#endif
}

static __inline void
bus_space_read_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
			bus_size_t offset, u_int16_t *addr, size_t count)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
	{
		int __x __asm__("%eax");
		__asm __volatile("				\n\
			cld					\n\
		1:	inw %w1,%%ax				\n\
			stosw					\n\
			addl $2,%1				\n\
			loop 1b"				:
		    "=&a" (__x)					:
		    "d" (bsh + offset), "D" (addr), "c" (count)	:
		    "%edx", "%edi", "%ecx", "memory");
	}
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		__asm __volatile("				\n\
			cld					\n\
			repne					\n\
			movsw"					:
								:
		    "S" (bsh + offset), "D" (addr), "c" (count)	:
		    "%esi", "%edi", "%ecx", "memory");
	}
#endif
}

static __inline void
bus_space_read_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
			bus_size_t offset, u_int32_t *addr, size_t count)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
	{
		int __x __asm__("%eax");
		__asm __volatile("				\n\
			cld					\n\
		1:	inl %w1,%%eax				\n\
			stosl					\n\
			addl $4,%1				\n\
			loop 1b"				:
		    "=&a" (__x)					:
		    "d" (bsh + offset), "D" (addr), "c" (count)	:
		    "%edx", "%edi", "%ecx", "memory");
	}
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		__asm __volatile("				\n\
			cld					\n\
			repne					\n\
			movsl"					:
								:
		    "S" (bsh + offset), "D" (addr), "c" (count)	:
		    "%esi", "%edi", "%ecx", "memory");
	}
#endif
}

#if 0	/* Cause a link error for bus_space_read_region_8 */
#define	bus_space_read_region_8	!!! bus_space_read_region_8 unimplemented !!!
#endif

/*
 * Write the 1, 2, 4, or 8 byte value `value' to bus space
 * described by tag/handle/offset.
 */

static __inline void bus_space_write_1(bus_space_tag_t tag,
				       bus_space_handle_t bsh,
				       bus_size_t offset, u_int8_t value);

static __inline void bus_space_write_2(bus_space_tag_t tag,
				       bus_space_handle_t bsh,
				       bus_size_t offset, u_int16_t value);

static __inline void bus_space_write_4(bus_space_tag_t tag,
				       bus_space_handle_t bsh,
				       bus_size_t offset, u_int32_t value);

static __inline void
bus_space_write_1(bus_space_tag_t tag, bus_space_handle_t bsh,
		       bus_size_t offset, u_int8_t value)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		outb(bsh + offset, value);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
		*(volatile u_int8_t *)(bsh + offset) = value;
#endif
}

static __inline void
bus_space_write_2(bus_space_tag_t tag, bus_space_handle_t bsh,
		       bus_size_t offset, u_int16_t value)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		outw(bsh + offset, value);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
		*(volatile u_int16_t *)(bsh + offset) = value;
#endif
}

static __inline void
bus_space_write_4(bus_space_tag_t tag, bus_space_handle_t bsh,
		       bus_size_t offset, u_int32_t value)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		outl(bsh + offset, value);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
		*(volatile u_int32_t *)(bsh + offset) = value;
#endif
}

#if 0	/* Cause a link error for bus_space_write_8 */
#define	bus_space_write_8	!!! bus_space_write_8 not implemented !!!
#endif

/*
 * Write `count' 1, 2, 4, or 8 byte quantities from the buffer
 * provided to bus space described by tag/handle/offset.
 */

static __inline void bus_space_write_multi_1(bus_space_tag_t tag,
					     bus_space_handle_t bsh,
					     bus_size_t offset,
					     const u_int8_t *addr,
					     size_t count);
static __inline void bus_space_write_multi_2(bus_space_tag_t tag,
					     bus_space_handle_t bsh,
					     bus_size_t offset,
					     const u_int16_t *addr,
					     size_t count);

static __inline void bus_space_write_multi_4(bus_space_tag_t tag,
					     bus_space_handle_t bsh,
					     bus_size_t offset,
					     const u_int32_t *addr,
					     size_t count);

static __inline void
bus_space_write_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
			bus_size_t offset, const u_int8_t *addr, size_t count)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		outsb(bsh + offset, addr, count);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		int __x __asm__("%eax");
		__asm __volatile("				\n\
			cld					\n\
		1:	lodsb					\n\
			movb %%al,(%1)				\n\
			loop 1b"				:
		    "=&a" (__x)					:
		    "r" (bsh + offset), "S" (addr), "c" (count)	:
		    "%esi", "%ecx");
	}
#endif
}

static __inline void
bus_space_write_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
			bus_size_t offset, const u_int16_t *addr, size_t count)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		outsw(bsh + offset, addr, count);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		int __x __asm__("%eax");
		__asm __volatile("				\n\
			cld					\n\
		1:	lodsw					\n\
			movw %%ax,(%1)				\n\
			loop 1b"				:
		    "=&a" (__x)					:
		    "r" (bsh + offset), "S" (addr), "c" (count)	:
		    "%esi", "%ecx");
	}
#endif
}

static __inline void
bus_space_write_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
			bus_size_t offset, const u_int32_t *addr, size_t count)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		outsl(bsh + offset, addr, count);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		int __x __asm__("%eax");
		__asm __volatile("				\n\
			cld					\n\
		1:	lodsl					\n\
			movl %%eax,(%1)				\n\
			loop 1b"				:
		    "=&a" (__x)					:
		    "r" (bsh + offset), "S" (addr), "c" (count)	:
		    "%esi", "%ecx");
	}
#endif
}

#if 0	/* Cause a link error for bus_space_write_multi_8 */
#define	bus_space_write_multi_8(t, h, o, a, c)				\
			!!! bus_space_write_multi_8 unimplemented !!!
#endif

/*
 * Write `count' 1, 2, 4, or 8 byte quantities from the buffer provided
 * to bus space described by tag/handle starting at `offset'.
 */

static __inline void bus_space_write_region_1(bus_space_tag_t tag,
					      bus_space_handle_t bsh,
					      bus_size_t offset,
					      const u_int8_t *addr,
					      size_t count);
static __inline void bus_space_write_region_2(bus_space_tag_t tag,
					      bus_space_handle_t bsh,
					      bus_size_t offset,
					      const u_int16_t *addr,
					      size_t count);
static __inline void bus_space_write_region_4(bus_space_tag_t tag,
					      bus_space_handle_t bsh,
					      bus_size_t offset,
					      const u_int32_t *addr,
					      size_t count);

static __inline void
bus_space_write_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
			 bus_size_t offset, const u_int8_t *addr, size_t count)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
	{
		int __x __asm__("%eax");
		__asm __volatile("				\n\
			cld					\n\
		1:	lodsb					\n\
			outb %%al,%w1				\n\
			incl %1					\n\
			loop 1b"				:
		    "=&a" (__x)					:
		    "d" (bsh + offset), "S" (addr), "c" (count)	:
		    "%edx", "%esi", "%ecx", "memory");
	}
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		__asm __volatile("				\n\
			cld					\n\
			repne					\n\
			movsb"					:
								:
		    "D" (bsh + offset), "S" (addr), "c" (count)	:
		    "%edi", "%esi", "%ecx", "memory");
	}
#endif
}

static __inline void
bus_space_write_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
			 bus_size_t offset, const u_int16_t *addr, size_t count)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
	{
		int __x __asm__("%eax");
		__asm __volatile("				\n\
			cld					\n\
		1:	lodsw					\n\
			outw %%ax,%w1				\n\
			addl $2,%1				\n\
			loop 1b"				:
		    "=&a" (__x)					:
		    "d" (bsh + offset), "S" (addr), "c" (count)	:
		    "%edx", "%esi", "%ecx", "memory");
	}
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		__asm __volatile("				\n\
			cld					\n\
			repne					\n\
			movsw"					:
								:
		    "D" (bsh + offset), "S" (addr), "c" (count)	:
		    "%edi", "%esi", "%ecx", "memory");
	}
#endif
}

static __inline void
bus_space_write_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
			 bus_size_t offset, const u_int32_t *addr, size_t count)
{
#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
	{
		int __x __asm__("%eax");
		__asm __volatile("				\n\
			cld					\n\
		1:	lodsl					\n\
			outl %%eax,%w1				\n\
			addl $4,%1				\n\
			loop 1b"				:
		    "=&a" (__x)					:
		    "d" (bsh + offset), "S" (addr), "c" (count)	:
		    "%edx", "%esi", "%ecx", "memory");
	}
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		__asm __volatile("				\n\
			cld					\n\
			repne					\n\
			movsl"					:
								:
		    "D" (bsh + offset), "S" (addr), "c" (count)	:
		    "%edi", "%esi", "%ecx", "memory");
	}
#endif
}

#if 0	/* Cause a link error for bus_space_write_region_8 */
#define	bus_space_write_region_8					\
			!!! bus_space_write_region_8 unimplemented !!!
#endif

/*
 * Write the 1, 2, 4, or 8 byte value `val' to bus space described
 * by tag/handle/offset `count' times.
 */

static __inline void bus_space_set_multi_1(bus_space_tag_t tag,
					   bus_space_handle_t bsh,
					   bus_size_t offset,
					   u_int8_t value, size_t count);
static __inline void bus_space_set_multi_2(bus_space_tag_t tag,
					   bus_space_handle_t bsh,
					   bus_size_t offset,
					   u_int16_t value, size_t count);
static __inline void bus_space_set_multi_4(bus_space_tag_t tag,
					   bus_space_handle_t bsh,
					   bus_size_t offset,
					   u_int32_t value, size_t count);

static __inline void
bus_space_set_multi_1(bus_space_tag_t tag, bus_space_handle_t bsh,
		      bus_size_t offset, u_int8_t value, size_t count)
{
	bus_addr_t addr = bsh + offset;

#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		while (count--)
			outb(addr, value);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
		while (count--)
			*(volatile u_int8_t *)(addr) = value;
#endif
}

static __inline void
bus_space_set_multi_2(bus_space_tag_t tag, bus_space_handle_t bsh,
		     bus_size_t offset, u_int16_t value, size_t count)
{
	bus_addr_t addr = bsh + offset;

#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		while (count--)
			outw(addr, value);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
		while (count--)
			*(volatile u_int16_t *)(addr) = value;
#endif
}

static __inline void
bus_space_set_multi_4(bus_space_tag_t tag, bus_space_handle_t bsh,
		      bus_size_t offset, u_int32_t value, size_t count)
{
	bus_addr_t addr = bsh + offset;

#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		while (count--)
			outl(addr, value);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
		while (count--)
			*(volatile u_int32_t *)(addr) = value;
#endif
}

#if 0	/* Cause a link error for bus_space_set_multi_8 */
#define	bus_space_set_multi_8 !!! bus_space_set_multi_8 unimplemented !!!
#endif

/*
 * Write `count' 1, 2, 4, or 8 byte value `val' to bus space described
 * by tag/handle starting at `offset'.
 */

static __inline void bus_space_set_region_1(bus_space_tag_t tag,
					    bus_space_handle_t bsh,
					    bus_size_t offset, u_int8_t value,
					    size_t count);
static __inline void bus_space_set_region_2(bus_space_tag_t tag,
					    bus_space_handle_t bsh,
					    bus_size_t offset, u_int16_t value,
					    size_t count);
static __inline void bus_space_set_region_4(bus_space_tag_t tag,
					    bus_space_handle_t bsh,
					    bus_size_t offset, u_int32_t value,
					    size_t count);

static __inline void
bus_space_set_region_1(bus_space_tag_t tag, bus_space_handle_t bsh,
		       bus_size_t offset, u_int8_t value, size_t count)
{
	bus_addr_t addr = bsh + offset;

#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		for (; count != 0; count--, addr++)
			outb(addr, value);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
		for (; count != 0; count--, addr++)
			*(volatile u_int8_t *)(addr) = value;
#endif
}

static __inline void
bus_space_set_region_2(bus_space_tag_t tag, bus_space_handle_t bsh,
		       bus_size_t offset, u_int16_t value, size_t count)
{
	bus_addr_t addr = bsh + offset;

#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		for (; count != 0; count--, addr += 2)
			outw(addr, value);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
		for (; count != 0; count--, addr += 2)
			*(volatile u_int16_t *)(addr) = value;
#endif
}

static __inline void
bus_space_set_region_4(bus_space_tag_t tag, bus_space_handle_t bsh,
		       bus_size_t offset, u_int32_t value, size_t count)
{
	bus_addr_t addr = bsh + offset;

#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
		for (; count != 0; count--, addr += 4)
			outl(addr, value);
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
		for (; count != 0; count--, addr += 4)
			*(volatile u_int32_t *)(addr) = value;
#endif
}

#if 0	/* Cause a link error for bus_space_set_region_8 */
#define	bus_space_set_region_8	!!! bus_space_set_region_8 unimplemented !!!
#endif

/*
 * Copy `count' 1, 2, 4, or 8 byte values from bus space starting
 * at tag/bsh1/off1 to bus space starting at tag/bsh2/off2.
 */

static __inline void bus_space_copy_region_1(bus_space_tag_t tag,
					     bus_space_handle_t bsh1,
					     bus_size_t off1,
					     bus_space_handle_t bsh2,
					     bus_size_t off2, size_t count);

static __inline void bus_space_copy_region_2(bus_space_tag_t tag,
					     bus_space_handle_t bsh1,
					     bus_size_t off1,
					     bus_space_handle_t bsh2,
					     bus_size_t off2, size_t count);

static __inline void bus_space_copy_region_4(bus_space_tag_t tag,
					     bus_space_handle_t bsh1,
					     bus_size_t off1,
					     bus_space_handle_t bsh2,
					     bus_size_t off2, size_t count);

static __inline void
bus_space_copy_region_1(bus_space_tag_t tag, bus_space_handle_t bsh1,
			bus_size_t off1, bus_space_handle_t bsh2,
			bus_size_t off2, size_t count)
{
	bus_addr_t addr1 = bsh1 + off1;
	bus_addr_t addr2 = bsh2 + off2;

#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
	{
		if (addr1 >= addr2) {
			/* src after dest: copy forward */
			for (; count != 0; count--, addr1++, addr2++)
				outb(addr2, inb(addr1));
		} else {
			/* dest after src: copy backwards */
			for (addr1 += (count - 1), addr2 += (count - 1);
			    count != 0; count--, addr1--, addr2--)
				outb(addr2, inb(addr1));
		}
	}
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		if (addr1 >= addr2) {
			/* src after dest: copy forward */
			for (; count != 0; count--, addr1++, addr2++)
				*(volatile u_int8_t *)(addr2) =
				    *(volatile u_int8_t *)(addr1);
		} else {
			/* dest after src: copy backwards */
			for (addr1 += (count - 1), addr2 += (count - 1);
			    count != 0; count--, addr1--, addr2--)
				*(volatile u_int8_t *)(addr2) =
				    *(volatile u_int8_t *)(addr1);
		}
	}
#endif
}

static __inline void
bus_space_copy_region_2(bus_space_tag_t tag, bus_space_handle_t bsh1,
			bus_size_t off1, bus_space_handle_t bsh2,
			bus_size_t off2, size_t count)
{
	bus_addr_t addr1 = bsh1 + off1;
	bus_addr_t addr2 = bsh2 + off2;

#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
	{
		if (addr1 >= addr2) {
			/* src after dest: copy forward */
			for (; count != 0; count--, addr1 += 2, addr2 += 2)
				outw(addr2, inw(addr1));
		} else {
			/* dest after src: copy backwards */
			for (addr1 += 2 * (count - 1), addr2 += 2 * (count - 1);
			    count != 0; count--, addr1 -= 2, addr2 -= 2)
				outw(addr2, inw(addr1));
		}
	}
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		if (addr1 >= addr2) {
			/* src after dest: copy forward */
			for (; count != 0; count--, addr1 += 2, addr2 += 2)
				*(volatile u_int16_t *)(addr2) =
				    *(volatile u_int16_t *)(addr1);
		} else {
			/* dest after src: copy backwards */
			for (addr1 += 2 * (count - 1), addr2 += 2 * (count - 1);
			    count != 0; count--, addr1 -= 2, addr2 -= 2)
				*(volatile u_int16_t *)(addr2) =
				    *(volatile u_int16_t *)(addr1);
		}
	}
#endif
}

static __inline void
bus_space_copy_region_4(bus_space_tag_t tag, bus_space_handle_t bsh1,
			bus_size_t off1, bus_space_handle_t bsh2,
			bus_size_t off2, size_t count)
{
	bus_addr_t addr1 = bsh1 + off1;
	bus_addr_t addr2 = bsh2 + off2;

#if defined(_I386_BUS_PIO_H_)
#if defined(_I386_BUS_MEMIO_H_)
	if (tag == I386_BUS_SPACE_IO)
#endif
	{
		if (addr1 >= addr2) {
			/* src after dest: copy forward */
			for (; count != 0; count--, addr1 += 4, addr2 += 4)
				outl(addr2, inl(addr1));
		} else {
			/* dest after src: copy backwards */
			for (addr1 += 4 * (count - 1), addr2 += 4 * (count - 1);
			    count != 0; count--, addr1 -= 4, addr2 -= 4)
				outl(addr2, inl(addr1));
		}
	}
#endif
#if defined(_I386_BUS_MEMIO_H_)
#if defined(_I386_BUS_PIO_H_)
	else
#endif
	{
		if (addr1 >= addr2) {
			/* src after dest: copy forward */
			for (; count != 0; count--, addr1 += 4, addr2 += 4)
				*(volatile u_int32_t *)(addr2) =
				    *(volatile u_int32_t *)(addr1);
		} else {
			/* dest after src: copy backwards */
			for (addr1 += 4 * (count - 1), addr2 += 4 * (count - 1);
			    count != 0; count--, addr1 -= 4, addr2 -= 4)
				*(volatile u_int32_t *)(addr2) =
				    *(volatile u_int32_t *)(addr1);
		}
	}
#endif
}

#endif /* defined(_I386_BUS_PIO_H_) || defined(_I386_MEM_IO_H_) */

#if 0	/* Cause a link error for bus_space_copy_8 */
#define	bus_space_copy_region_8	!!! bus_space_copy_region_8 unimplemented !!!
#endif

/*
 * Bus read/write barrier methods.
 *
 *	void bus_space_barrier(bus_space_tag_t tag, bus_space_handle_t bsh,
 *			       bus_size_t offset, bus_size_t len, int flags);
 *
 * Note: the i386 does not currently require barriers, but we must
 * provide the flags to MI code.
 */
#define	bus_space_barrier(t, h, o, l, f)	\
	((void)((void)(t), (void)(h), (void)(o), (void)(l), (void)(f)))
#define	BUS_SPACE_BARRIER_READ	0x01		/* force read barrier */
#define	BUS_SPACE_BARRIER_WRITE	0x02		/* force write barrier */

/*
 * Flags used in various bus DMA methods.
 */
#define	BUS_DMA_WAITOK		0x00	/* safe to sleep (pseudo-flag) */
#define	BUS_DMA_NOWAIT		0x01	/* not safe to sleep */
#define	BUS_DMA_ALLOCNOW	0x02	/* perform resource allocation now */
#define	BUS_DMAMEM_NOSYNC	0x04	/* map memory to not require sync */
#define	BUS_DMA_BUS1		0x10	/* placeholders for bus functions... */
#define	BUS_DMA_BUS2		0x20
#define	BUS_DMA_BUS3		0x40
#define	BUS_DMA_BUS4		0x80

/* Forwards needed by prototypes below. */
struct mbuf;
struct uio;

/*
 *	bus_dmasync_op_t
 *
 *	Operations performed by bus_dmamap_sync().
 */
typedef enum {
	BUS_DMASYNC_PREREAD,
	BUS_DMASYNC_POSTREAD,
	BUS_DMASYNC_PREWRITE,
	BUS_DMASYNC_POSTWRITE
} bus_dmasync_op_t;

/*
 *	bus_dma_tag_t
 *
 *	A machine-dependent opaque type describing the characteristics
 *	of how to perform DMA mappings.  This structure encapsultes
 *	information concerning address and alignment restrictions, number
 *	of S/G	segments, amount of data per S/G segment, etc.
 */
typedef struct bus_dma_tag	*bus_dma_tag_t;

/*
 *	bus_dmamap_t
 *
 *	DMA mapping instance information.
 */
typedef struct bus_dmamap	*bus_dmamap_t;

/*
 *	bus_dma_segment_t
 *
 *	Describes a single contiguous DMA transaction.  Values
 *	are suitable for programming into DMA registers.
 */
typedef struct bus_dma_segment {
	bus_addr_t	ds_addr;	/* DMA address */
	bus_size_t	ds_len;		/* length of transfer */
} bus_dma_segment_t;

/*
 * A function that returns 1 if the address cannot be accessed by
 * a device and 0 if it can be.
 */
typedef int bus_dma_filter_t(void *, bus_addr_t);

/*
 * Allocate a device specific dma_tag encapsulating the constraints of
 * the parent tag in addition to other restrictions specified:
 *
 *	alignment:	alignment for segments.
 *	boundary:	Boundary that segments cannot cross.
 *	lowaddr:	Low restricted address that cannot appear in a mapping.
 *	highaddr:	High restricted address that cannot appear in a mapping.
 *	filtfunc:	An optional function to further test if an address
 *			within the range of lowaddr and highaddr cannot appear
 *			in a mapping.
 *	filtfuncarg:	An argument that will be passed to filtfunc in addition
 *			to the address to test.
 *	maxsize:	Maximum mapping size supported by this tag.
 *	nsegments:	Number of discontinuities allowed in maps.
 *	maxsegsz:	Maximum size of a segment in the map.
 *	flags:		Bus DMA flags.
 *	dmat:		A pointer to set to a valid dma tag should the return
 *			value of this function indicate success.
 */
/* XXX Should probably allow specification of alignment */
int bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignemnt,
		       bus_size_t boundary, bus_addr_t lowaddr,
		       bus_addr_t highaddr, bus_dma_filter_t *filtfunc,
		       void *filtfuncarg, bus_size_t maxsize, int nsegments,
		       bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat);

int bus_dma_tag_destroy(bus_dma_tag_t dmat);

/*
 * Allocate a handle for mapping from kva/uva/physical
 * address space into bus device space.
 */
int bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp);

/*
 * Destroy  a handle for mapping from kva/uva/physical
 * address space into bus device space.
 */
int bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map);

/*
 * Allocate a piece of memory that can be efficiently mapped into
 * bus device space based on the constraints lited in the dma tag.
 * A dmamap to for use with dmamap_load is also allocated.
 */
int bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
		     bus_dmamap_t *mapp);

/*
 * Free a piece of memory and it's allociated dmamap, that was allocated
 * via bus_dmamem_alloc.
 */
void bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map);

/*
 * A function that processes a successfully loaded dma map or an error
 * from a delayed load map.
 */
typedef void bus_dmamap_callback_t(void *, bus_dma_segment_t *, int, int);

/*
 * Map the buffer buf into bus space using the dmamap map.
 */
int bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
		    bus_size_t buflen, bus_dmamap_callback_t *callback,
		    void *callback_arg, int flags);

/*
 * Perform a syncronization operation on the given map.
 */
void _bus_dmamap_sync(bus_dma_tag_t, bus_dmamap_t, bus_dmasync_op_t);
#define bus_dmamap_sync(dmat, dmamap, op) 		\
	if ((dmamap) != NULL)				\
		_bus_dmamap_sync(dmat, dmamap, op)

/*
 * Release the mapping held by map.
 */
void _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map);
#define bus_dmamap_unload(dmat, dmamap) 		\
	if ((dmamap) != NULL)				\
		_bus_dmamap_unload(dmat, dmamap)

#endif /* _I386_BUS_H_ */