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b168057a | 1 | /* Copyright (C) 1998-2015 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> | |
40 | #include <string.h> | |
41 | #include <unistd.h> | |
42 | ||
43 | #include <sys/types.h> | |
44 | #include <sys/mman.h> | |
45 | ||
efaef362 | 46 | #include <linux/version.h> |
aba75488 | 47 | #include <sys/sysctl.h> |
3d72808b UD |
48 | |
49 | #define PATH_ARM_SYSTYPE "/etc/arm_systype" | |
50 | #define PATH_CPUINFO "/proc/cpuinfo" | |
51 | ||
52 | #define MAX_PORT 0x10000 | |
53 | ||
54 | static struct { | |
55 | unsigned long int base; | |
56 | unsigned long int io_base; | |
57 | unsigned int shift; | |
58 | unsigned int initdone; /* since all the above could be 0 */ | |
59 | } io; | |
60 | ||
61 | #define IO_BASE_FOOTBRIDGE 0x7c000000 | |
62 | #define IO_SHIFT_FOOTBRIDGE 0 | |
63 | ||
64 | static struct platform { | |
65 | const char *name; | |
66 | unsigned long int io_base; | |
67 | unsigned int shift; | |
68 | } platform[] = { | |
69 | /* All currently supported platforms are in fact the same. :-) */ | |
70 | {"Chalice-CATS", IO_BASE_FOOTBRIDGE, IO_SHIFT_FOOTBRIDGE}, | |
71 | {"DEC-EBSA285", IO_BASE_FOOTBRIDGE, IO_SHIFT_FOOTBRIDGE}, | |
72 | {"Corel-NetWinder", IO_BASE_FOOTBRIDGE, IO_SHIFT_FOOTBRIDGE}, | |
58d7604e | 73 | {"Rebel-NetWinder", IO_BASE_FOOTBRIDGE, IO_SHIFT_FOOTBRIDGE}, |
3d72808b UD |
74 | }; |
75 | ||
76 | #define IO_ADDR(port) (io.base + ((port) << io.shift)) | |
77 | ||
78 | /* | |
aba75488 UD |
79 | * Initialize I/O system. There are several ways to get the information |
80 | * we need. Each is tried in turn until one succeeds. | |
81 | * | |
efaef362 | 82 | * 1. Sysctl (CTL_BUS, CTL_BUS_ISA, ISA_*). This is the preferred method |
aba75488 UD |
83 | * but not all kernels support it. |
84 | * | |
85 | * 2. Read the value (not the contents) of symlink PATH_ARM_SYSTYPE. | |
86 | * - If it matches one of the entries in the table above, use the | |
87 | * corresponding values. | |
88 | * - If it begins with a number, assume this is a previously | |
89 | * unsupported system and the values encode, in order, | |
90 | * "<io_base>,<port_shift>". | |
3d72808b | 91 | * |
aba75488 UD |
92 | * 3. Lookup the "system type" field in /proc/cpuinfo. Again, if it |
93 | * matches an entry in the platform[] table, use the corresponding | |
94 | * values. | |
3d72808b UD |
95 | */ |
96 | ||
efaef362 PB |
97 | /* The Linux kernel headers renamed this constant between 2.5.26 and |
98 | 2.5.27. It was backported to 2.4 between 2.4.22 and 2.4.23. */ | |
99 | #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,23) | |
100 | # define BUS_ISA CTL_BUS_ISA | |
101 | #endif | |
102 | ||
3d72808b UD |
103 | static int |
104 | init_iosys (void) | |
105 | { | |
106 | char systype[256]; | |
107 | int i, n; | |
aba75488 UD |
108 | static int iobase_name[] = { CTL_BUS, BUS_ISA, BUS_ISA_PORT_BASE }; |
109 | static int ioshift_name[] = { CTL_BUS, BUS_ISA, BUS_ISA_PORT_SHIFT }; | |
110 | size_t len = sizeof(io.base); | |
111 | ||
5de92c17 JM |
112 | if (! __sysctl (iobase_name, 3, &io.io_base, &len, NULL, 0) |
113 | && ! __sysctl (ioshift_name, 3, &io.shift, &len, NULL, 0)) | |
aba75488 UD |
114 | { |
115 | io.initdone = 1; | |
116 | return 0; | |
117 | } | |
3d72808b | 118 | |
5de92c17 | 119 | n = __readlink (PATH_ARM_SYSTYPE, systype, sizeof (systype) - 1); |
3d72808b UD |
120 | if (n > 0) |
121 | { | |
122 | systype[n] = '\0'; | |
123 | if (isdigit (systype[0])) | |
124 | { | |
125 | if (sscanf (systype, "%li,%i", &io.io_base, &io.shift) == 2) | |
126 | { | |
127 | io.initdone = 1; | |
128 | return 0; | |
129 | } | |
130 | /* else we're likely going to fail with the system match below */ | |
131 | } | |
132 | } | |
133 | else | |
134 | { | |
135 | FILE * fp; | |
136 | ||
84715d22 | 137 | fp = fopen (PATH_CPUINFO, "rce"); |
aba75488 | 138 | if (! fp) |
3d72808b UD |
139 | return -1; |
140 | while ((n = fscanf (fp, "Hardware\t: %256[^\n]\n", systype)) | |
141 | != EOF) | |
142 | { | |
143 | if (n == 1) | |
144 | break; | |
145 | else | |
5de92c17 | 146 | fgets_unlocked (systype, 256, fp); |
3d72808b UD |
147 | } |
148 | fclose (fp); | |
149 | ||
150 | if (n == EOF) | |
151 | { | |
152 | /* this can happen if the format of /proc/cpuinfo changes... */ | |
153 | fprintf (stderr, | |
154 | "ioperm: Unable to determine system type.\n" | |
155 | "\t(May need " PATH_ARM_SYSTYPE " symlink?)\n"); | |
156 | __set_errno (ENODEV); | |
157 | return -1; | |
158 | } | |
159 | } | |
160 | ||
161 | /* translate systype name into i/o system: */ | |
162 | for (i = 0; i < sizeof (platform) / sizeof (platform[0]); ++i) | |
163 | { | |
164 | if (strcmp (platform[i].name, systype) == 0) | |
165 | { | |
166 | io.shift = platform[i].shift; | |
167 | io.io_base = platform[i].io_base; | |
168 | io.initdone = 1; | |
169 | return 0; | |
170 | } | |
171 | } | |
172 | ||
173 | /* systype is not a known platform name... */ | |
2b6aa9b3 | 174 | __set_errno (ENODEV); |
3d72808b UD |
175 | return -1; |
176 | } | |
177 | ||
178 | int | |
179 | _ioperm (unsigned long int from, unsigned long int num, int turn_on) | |
180 | { | |
aba75488 | 181 | if (! io.initdone && init_iosys () < 0) |
3d72808b UD |
182 | return -1; |
183 | ||
184 | /* this test isn't as silly as it may look like; consider overflows! */ | |
185 | if (from >= MAX_PORT || from + num > MAX_PORT) | |
186 | { | |
187 | __set_errno (EINVAL); | |
188 | return -1; | |
189 | } | |
190 | ||
191 | if (turn_on) | |
192 | { | |
193 | if (! io.base) | |
194 | { | |
195 | int fd; | |
196 | ||
5de92c17 | 197 | fd = __open ("/dev/mem", O_RDWR); |
3d72808b UD |
198 | if (fd < 0) |
199 | return -1; | |
200 | ||
201 | io.base = | |
2b6aa9b3 UD |
202 | (unsigned long int) __mmap (0, MAX_PORT << io.shift, |
203 | PROT_READ | PROT_WRITE, | |
3d72808b | 204 | MAP_SHARED, fd, io.io_base); |
5de92c17 | 205 | __close (fd); |
3d72808b UD |
206 | if ((long) io.base == -1) |
207 | return -1; | |
208 | } | |
3d72808b | 209 | } |
3d72808b | 210 | |
aba75488 | 211 | return 0; |
3d72808b UD |
212 | } |
213 | ||
214 | ||
215 | int | |
216 | _iopl (unsigned int level) | |
217 | { | |
218 | if (level > 3) | |
219 | { | |
220 | __set_errno (EINVAL); | |
221 | return -1; | |
222 | } | |
223 | if (level) | |
224 | { | |
225 | return _ioperm (0, MAX_PORT, 1); | |
226 | } | |
227 | return 0; | |
228 | } | |
229 | ||
230 | ||
231 | void | |
232 | _outb (unsigned char b, unsigned long int port) | |
233 | { | |
3d72808b UD |
234 | *((volatile unsigned char *)(IO_ADDR (port))) = b; |
235 | } | |
236 | ||
237 | ||
238 | void | |
239 | _outw (unsigned short b, unsigned long int port) | |
240 | { | |
3d72808b UD |
241 | *((volatile unsigned short *)(IO_ADDR (port))) = b; |
242 | } | |
243 | ||
244 | ||
245 | void | |
246 | _outl (unsigned int b, unsigned long int port) | |
247 | { | |
3d72808b UD |
248 | *((volatile unsigned long *)(IO_ADDR (port))) = b; |
249 | } | |
250 | ||
251 | ||
252 | unsigned int | |
253 | _inb (unsigned long int port) | |
254 | { | |
255 | return *((volatile unsigned char *)(IO_ADDR (port))); | |
256 | } | |
257 | ||
258 | ||
259 | unsigned int | |
260 | _inw (unsigned long int port) | |
261 | { | |
262 | return *((volatile unsigned short *)(IO_ADDR (port))); | |
263 | } | |
264 | ||
265 | ||
266 | unsigned int | |
267 | _inl (unsigned long int port) | |
268 | { | |
269 | return *((volatile unsigned long *)(IO_ADDR (port))); | |
270 | } | |
271 | ||
272 | weak_alias (_ioperm, ioperm); | |
273 | weak_alias (_iopl, iopl); | |
274 | weak_alias (_inb, inb); | |
275 | weak_alias (_inw, inw); | |
276 | weak_alias (_inl, inl); | |
277 | weak_alias (_outb, outb); | |
278 | weak_alias (_outw, outw); | |
279 | weak_alias (_outl, outl); |