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bfff8b1b | 1 | /* Copyright (C) 1998-2017 Free Software Foundation, Inc. |
3d72808b UD |
2 | This file is part of the GNU C Library. |
3 | Contributed by Phil Blundell, based on the Alpha version by | |
4 | David Mosberger. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
3214b89b AJ |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
3d72808b UD |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
3214b89b | 14 | Lesser General Public License for more details. |
3d72808b | 15 | |
3214b89b | 16 | You should have received a copy of the GNU Lesser General Public |
ab84e3ff PE |
17 | License along with the GNU C Library. If not, see |
18 | <http://www.gnu.org/licenses/>. */ | |
3d72808b UD |
19 | |
20 | /* I/O port access on the ARM is something of a fiction. What we do is to | |
21 | map an appropriate area of /dev/mem into user space so that a program | |
22 | can blast away at the hardware in such a way as to generate I/O cycles | |
23 | on the bus. To insulate user code from dependencies on particular | |
24 | hardware we don't allow calls to inb() and friends to be inlined, but | |
25 | force them to come through code in here every time. Performance-critical | |
26 | registers tend to be memory mapped these days so this should be no big | |
27 | problem. */ | |
28 | ||
aba75488 UD |
29 | /* Once upon a time this file used mprotect to enable and disable |
30 | access to particular areas of I/O space. Unfortunately the | |
31 | mprotect syscall also has the side effect of enabling caching for | |
32 | the area affected (this is a kernel limitation). So we now just | |
33 | enable all the ports all of the time. */ | |
34 | ||
3d72808b UD |
35 | #include <errno.h> |
36 | #include <fcntl.h> | |
37 | #include <stdio.h> | |
38 | #include <ctype.h> | |
39 | #include <stdlib.h> | |
3d72808b UD |
40 | #include <unistd.h> |
41 | ||
42 | #include <sys/types.h> | |
43 | #include <sys/mman.h> | |
44 | ||
aba75488 | 45 | #include <sys/sysctl.h> |
3d72808b | 46 | |
3d72808b UD |
47 | #define MAX_PORT 0x10000 |
48 | ||
49 | static struct { | |
50 | unsigned long int base; | |
51 | unsigned long int io_base; | |
52 | unsigned int shift; | |
53 | unsigned int initdone; /* since all the above could be 0 */ | |
54 | } io; | |
55 | ||
3d72808b UD |
56 | #define IO_ADDR(port) (io.base + ((port) << io.shift)) |
57 | ||
58 | /* | |
cc42170e AJ |
59 | * Initialize I/O system. The io_bae and port_shift values are fetched |
60 | * using sysctl (CTL_BUS, CTL_BUS_ISA, ISA_*). | |
3d72808b UD |
61 | */ |
62 | ||
63 | static int | |
64 | init_iosys (void) | |
65 | { | |
5db08777 AJ |
66 | static int iobase_name[] = { CTL_BUS, CTL_BUS_ISA, BUS_ISA_PORT_BASE }; |
67 | static int ioshift_name[] = { CTL_BUS, CTL_BUS_ISA, BUS_ISA_PORT_SHIFT }; | |
aba75488 UD |
68 | size_t len = sizeof(io.base); |
69 | ||
5de92c17 JM |
70 | if (! __sysctl (iobase_name, 3, &io.io_base, &len, NULL, 0) |
71 | && ! __sysctl (ioshift_name, 3, &io.shift, &len, NULL, 0)) | |
aba75488 UD |
72 | { |
73 | io.initdone = 1; | |
74 | return 0; | |
75 | } | |
3d72808b | 76 | |
cc42170e | 77 | /* sysctl has failed... */ |
2b6aa9b3 | 78 | __set_errno (ENODEV); |
3d72808b UD |
79 | return -1; |
80 | } | |
81 | ||
82 | int | |
83 | _ioperm (unsigned long int from, unsigned long int num, int turn_on) | |
84 | { | |
aba75488 | 85 | if (! io.initdone && init_iosys () < 0) |
3d72808b UD |
86 | return -1; |
87 | ||
88 | /* this test isn't as silly as it may look like; consider overflows! */ | |
89 | if (from >= MAX_PORT || from + num > MAX_PORT) | |
90 | { | |
91 | __set_errno (EINVAL); | |
92 | return -1; | |
93 | } | |
94 | ||
95 | if (turn_on) | |
96 | { | |
97 | if (! io.base) | |
98 | { | |
99 | int fd; | |
100 | ||
5de92c17 | 101 | fd = __open ("/dev/mem", O_RDWR); |
3d72808b UD |
102 | if (fd < 0) |
103 | return -1; | |
104 | ||
105 | io.base = | |
2b6aa9b3 UD |
106 | (unsigned long int) __mmap (0, MAX_PORT << io.shift, |
107 | PROT_READ | PROT_WRITE, | |
3d72808b | 108 | MAP_SHARED, fd, io.io_base); |
5de92c17 | 109 | __close (fd); |
3d72808b UD |
110 | if ((long) io.base == -1) |
111 | return -1; | |
112 | } | |
3d72808b | 113 | } |
3d72808b | 114 | |
aba75488 | 115 | return 0; |
3d72808b UD |
116 | } |
117 | ||
118 | ||
119 | int | |
120 | _iopl (unsigned int level) | |
121 | { | |
122 | if (level > 3) | |
123 | { | |
124 | __set_errno (EINVAL); | |
125 | return -1; | |
126 | } | |
127 | if (level) | |
128 | { | |
129 | return _ioperm (0, MAX_PORT, 1); | |
130 | } | |
131 | return 0; | |
132 | } | |
133 | ||
134 | ||
135 | void | |
136 | _outb (unsigned char b, unsigned long int port) | |
137 | { | |
3d72808b UD |
138 | *((volatile unsigned char *)(IO_ADDR (port))) = b; |
139 | } | |
140 | ||
141 | ||
142 | void | |
143 | _outw (unsigned short b, unsigned long int port) | |
144 | { | |
3d72808b UD |
145 | *((volatile unsigned short *)(IO_ADDR (port))) = b; |
146 | } | |
147 | ||
148 | ||
149 | void | |
150 | _outl (unsigned int b, unsigned long int port) | |
151 | { | |
3d72808b UD |
152 | *((volatile unsigned long *)(IO_ADDR (port))) = b; |
153 | } | |
154 | ||
155 | ||
156 | unsigned int | |
157 | _inb (unsigned long int port) | |
158 | { | |
159 | return *((volatile unsigned char *)(IO_ADDR (port))); | |
160 | } | |
161 | ||
162 | ||
163 | unsigned int | |
164 | _inw (unsigned long int port) | |
165 | { | |
166 | return *((volatile unsigned short *)(IO_ADDR (port))); | |
167 | } | |
168 | ||
169 | ||
170 | unsigned int | |
171 | _inl (unsigned long int port) | |
172 | { | |
173 | return *((volatile unsigned long *)(IO_ADDR (port))); | |
174 | } | |
175 | ||
176 | weak_alias (_ioperm, ioperm); | |
177 | weak_alias (_iopl, iopl); | |
178 | weak_alias (_inb, inb); | |
179 | weak_alias (_inw, inw); | |
180 | weak_alias (_inl, inl); | |
181 | weak_alias (_outb, outb); | |
182 | weak_alias (_outw, outw); | |
183 | weak_alias (_outl, outl); |