xref: /aosp_15_r20/bionic/libc/include/sys/io.h (revision 8d67ca893c1523eb926b9080dbe4e2ffd2a27ba1)
1 /*
2  * Copyright (C) 2024 The Android Open Source Project
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  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #pragma once
30 
31 /**
32  * @file sys/io.h
33  * @brief The x86/x86-64 I/O port functions iopl() and ioperm().
34  */
35 
36 #include <sys/cdefs.h>
37 
38 #include <errno.h>
39 #include <sys/syscall.h>
40 #include <unistd.h>
41 
42 __BEGIN_DECLS
43 
44 /**
45  * [iopl(2)](https://man7.org/linux/man-pages/man2/iopl.2.html) changes the I/O
46  * privilege level for all x86/x8-64 I/O ports, for the calling thread.
47  *
48  * New callers should use ioperm() instead.
49  *
50  * Returns 0 on success, and returns -1 and sets `errno` on failure.
51  *
52  * Only available for x86/x86-64.
53  */
54 #if defined(__NR_iopl)
iopl(int __level)55 __attribute__((__deprecated__("use ioperm() instead"))) static __inline int iopl(int __level) {
56   return syscall(__NR_iopl, __level);
57 }
58 #endif
59 
60 /**
61  * [ioperm(2)](https://man7.org/linux/man-pages/man2/ioperm.2.html) sets the I/O
62  * permissions for the given number of x86/x86-64 I/O ports, starting at the
63  * given port.
64  *
65  * Returns 0 on success, and returns -1 and sets `errno` on failure.
66  *
67  * Only available for x86/x86-64.
68  */
69 #if defined(__NR_iopl)
ioperm(unsigned long __from,unsigned long __n,int __enabled)70 static __inline int ioperm(unsigned long __from, unsigned long __n, int __enabled) {
71   return syscall(__NR_ioperm, __from, __n, __enabled);
72 }
73 #endif
74 
75 __END_DECLS
76