FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/io.c
1 /*-
2 * Copyright (c) 2004 Mark R V Murray
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/8.0/sys/i386/i386/io.c 164033 2006-11-06 13:42:10Z rwatson $");
29
30 #include <sys/param.h>
31 #include <sys/conf.h>
32 #include <sys/fcntl.h>
33 #include <sys/lock.h>
34 #include <sys/malloc.h>
35 #include <sys/mutex.h>
36 #include <sys/priv.h>
37 #include <sys/proc.h>
38 #include <sys/signalvar.h>
39 #include <sys/systm.h>
40
41 #include <machine/db_machdep.h>
42 #include <machine/frame.h>
43 #include <machine/psl.h>
44 #include <machine/specialreg.h>
45
46 #include <vm/vm.h>
47 #include <vm/pmap.h>
48
49 #include <machine/iodev.h>
50
51 /* ARGSUSED */
52 int
53 ioopen(struct cdev *dev __unused, int flags __unused, int fmt __unused,
54 struct thread *td)
55 {
56 int error;
57
58 error = priv_check(td, PRIV_IO);
59 if (error != 0)
60 return (error);
61 error = securelevel_gt(td->td_ucred, 0);
62 if (error != 0)
63 return (error);
64
65 td->td_frame->tf_eflags |= PSL_IOPL;
66
67 return (0);
68 }
69
70 /* ARGSUSED */
71 int
72 ioclose(struct cdev *dev __unused, int flags __unused, int fmt __unused,
73 struct thread *td)
74 {
75 td->td_frame->tf_eflags &= ~PSL_IOPL;
76
77 return (0);
78 }
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