FreeBSD/Linux Kernel Cross Reference
sys/i386/iopb.h
1 /*
2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
4 * All Rights Reserved.
5 *
6 * Permission to use, copy, modify and distribute this software and its
7 * documentation is hereby granted, provided that both the copyright
8 * notice and this permission notice appear in all copies of the
9 * software, derivative works or modified versions, and any portions
10 * thereof, and that both notices appear in supporting documentation.
11 *
12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
13 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15 *
16 * Carnegie Mellon requests users of this software to return to
17 *
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
22 *
23 * any improvements or extensions that they make and grant Carnegie Mellon
24 * the rights to redistribute these changes.
25 */
26
27 /*
28 * HISTORY
29 * $Log: iopb.h,v $
30 * Revision 2.4 93/09/01 11:32:45 mrt
31 * Support for 64k bit io bitmaps.
32 * [93/08/19 rvb]
33 *
34 * Revision 2.3 91/05/14 16:10:04 mrt
35 * Correcting copyright
36 *
37 * Revision 2.2 91/05/08 12:38:46 dbg
38 * Created.
39 * [91/03/21 dbg]
40 *
41 */
42
43 #ifndef _I386_IOPB_H_
44 #define _I386_IOPB_H_
45
46 #include <i386/tss.h>
47 #include <kern/queue.h>
48
49 /*
50 * IO permission bitmap.
51 *
52 * Allows only IO ports 0 .. 0x3ff: for ISA machines.
53 */
54
55 #define iopb_howmany(a,b) (((a)+(b)-1)/(b))
56
57 #define IOPB_MAX 0xffff /* ISA bus allows ports 0..3ff */
58 /* but accelerator cards are funky */
59 #define IOPB_BYTES (iopb_howmany(IOPB_MAX+1,8))
60
61 typedef unsigned char isa_iopb[IOPB_BYTES];
62
63 /*
64 * An IO permission map is a task segment with an IO permission bitmap.
65 */
66
67 struct iopb_tss {
68 struct i386_tss tss; /* task state segment */
69 isa_iopb bitmap; /* bitmap of mapped IO ports */
70 unsigned int barrier; /* bitmap barrier for CPU slop */
71 queue_head_t io_port_list; /* list of mapped IO ports */
72 int iopb_desc[2]; /* descriptor for this TSS */
73 };
74
75 typedef struct iopb_tss *iopb_tss_t;
76
77 #endif /* _I386_IOPB_H_ */
78
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