FreeBSD/Linux Kernel Cross Reference
sys/amd64/amd64/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("$FreeBSD$");
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/proc.h>
37 #include <sys/signalvar.h>
38 #include <sys/systm.h>
39
40 #include <machine/db_machdep.h>
41 #include <machine/frame.h>
42 #include <machine/psl.h>
43 #include <machine/specialreg.h>
44
45 #include <vm/vm.h>
46 #include <vm/pmap.h>
47
48 #include <machine/iodev.h>
49
50 /* ARGSUSED */
51 int
52 ioopen(struct cdev *dev __unused, int flags __unused, int fmt __unused,
53 struct thread *td)
54 {
55 int error;
56
57 error = suser(td);
58 if (error != 0)
59 return (error);
60 error = securelevel_gt(td->td_ucred, 0);
61 if (error != 0)
62 return (error);
63
64 td->td_frame->tf_rflags |= PSL_IOPL;
65
66 return (0);
67 }
68
69 /* ARGSUSED */
70 int
71 ioclose(struct cdev *dev __unused, int flags __unused, int fmt __unused,
72 struct thread *td)
73 {
74 td->td_frame->tf_rflags &= ~PSL_IOPL;
75
76 return (0);
77 }
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