1 | /* Copyright (C) 1999-2022 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | /* I/O access is restricted to ISA port space (ports 0..65535). |
19 | Modern devices hopefully are sane enough not to put any performance |
20 | critical registers in i/o space. |
21 | |
22 | On the first call to ioperm() or iopl(), the entire (E)ISA port |
23 | space is mapped into the virtual address space at address io.base. |
24 | mprotect() calls are then used to enable/disable access to ports. |
25 | Per 4KB page, there are 4 I/O ports. */ |
26 | |
27 | #include <errno.h> |
28 | #include <fcntl.h> |
29 | #include <ctype.h> |
30 | #include <stdlib.h> |
31 | #include <string.h> |
32 | #include <unistd.h> |
33 | |
34 | #include <sys/types.h> |
35 | #include <sys/mman.h> |
36 | |
37 | #define MAX_PORT 0x10000 |
38 | |
39 | /* |
40 | * Memory fence w/accept. This should never be used in code that is |
41 | * not IA-64 specific. |
42 | */ |
43 | #define __ia64_mf_a() __asm__ __volatile__ ("mf.a" ::: "memory") |
44 | |
45 | static struct |
46 | { |
47 | unsigned long int base; |
48 | unsigned long int page_mask; |
49 | } |
50 | io; |
51 | |
52 | __inline__ unsigned long int |
53 | io_offset (unsigned long int port) |
54 | { |
55 | return ((port >> 2) << 12) | (port & 0xfff); |
56 | } |
57 | |
58 | int |
59 | _ioperm (unsigned long int from, unsigned long int num, int turn_on) |
60 | { |
61 | unsigned long int base; |
62 | |
63 | /* this test isn't as silly as it may look like; consider overflows! */ |
64 | if (from >= MAX_PORT || from + num > MAX_PORT) |
65 | { |
66 | __set_errno (EINVAL); |
67 | return -1; |
68 | } |
69 | |
70 | if (turn_on) |
71 | { |
72 | if (!io.base) |
73 | { |
74 | unsigned long phys_io_base, len; |
75 | int fd; |
76 | |
77 | io.page_mask = ~(__getpagesize() - 1); |
78 | |
79 | /* get I/O base physical address from ar.k0 as per PRM: */ |
80 | __asm__ ("mov %0=ar.k0" : "=r" (phys_io_base)); |
81 | |
82 | /* The O_SYNC flag tells the /dev/mem driver to map the |
83 | memory uncached: */ |
84 | fd = __open ("/dev/mem" , O_RDWR | O_SYNC); |
85 | if (fd < 0) |
86 | return -1; |
87 | |
88 | len = io_offset (MAX_PORT); |
89 | /* see comment below */ |
90 | base = (unsigned long int) __mmap (0, len, PROT_READ | PROT_WRITE, MAP_SHARED, |
91 | fd, phys_io_base); |
92 | __close (fd); |
93 | |
94 | if ((long) base == -1) |
95 | return -1; |
96 | |
97 | io.base = base; |
98 | } |
99 | } |
100 | else |
101 | { |
102 | if (!io.base) |
103 | return 0; /* never was turned on... */ |
104 | } |
105 | |
106 | /* We can't do mprotect because that would cause us to lose the |
107 | uncached flag that the /dev/mem driver turned on. A MAP_UNCACHED |
108 | flag seems so much cleaner... |
109 | |
110 | See the history of this file for a version that tried mprotect. */ |
111 | return 0; |
112 | } |
113 | |
114 | int |
115 | _iopl (unsigned int level) |
116 | { |
117 | if (level > 3) |
118 | { |
119 | __set_errno (EINVAL); |
120 | return -1; |
121 | } |
122 | if (level) |
123 | { |
124 | int retval = _ioperm (from: 0, MAX_PORT, turn_on: 1); |
125 | /* Match the documented error returns of the x86 version. */ |
126 | if (retval < 0 && errno == EACCES) |
127 | __set_errno (EPERM); |
128 | return retval; |
129 | } |
130 | return 0; |
131 | } |
132 | |
133 | unsigned int |
134 | _inb (unsigned long int port) |
135 | { |
136 | volatile unsigned char *addr = (void *) io.base + io_offset (port); |
137 | unsigned char ret; |
138 | |
139 | ret = *addr; |
140 | __ia64_mf_a(); |
141 | return ret; |
142 | } |
143 | |
144 | unsigned int |
145 | _inw (unsigned long int port) |
146 | { |
147 | volatile unsigned short *addr = (void *) io.base + io_offset (port); |
148 | unsigned short ret; |
149 | |
150 | ret = *addr; |
151 | __ia64_mf_a(); |
152 | return ret; |
153 | } |
154 | |
155 | unsigned int |
156 | _inl (unsigned long int port) |
157 | { |
158 | volatile unsigned int *addr = (void *) io.base + io_offset (port); |
159 | unsigned int ret; |
160 | |
161 | ret = *addr; |
162 | __ia64_mf_a(); |
163 | return ret; |
164 | } |
165 | |
166 | void |
167 | _outb (unsigned char val, unsigned long int port) |
168 | { |
169 | volatile unsigned char *addr = (void *) io.base + io_offset (port); |
170 | |
171 | *addr = val; |
172 | __ia64_mf_a(); |
173 | } |
174 | |
175 | void |
176 | _outw (unsigned short val, unsigned long int port) |
177 | { |
178 | volatile unsigned short *addr = (void *) io.base + io_offset (port); |
179 | |
180 | *addr = val; |
181 | __ia64_mf_a(); |
182 | } |
183 | |
184 | void |
185 | _outl (unsigned int val, unsigned long int port) |
186 | { |
187 | volatile unsigned int *addr = (void *) io.base + io_offset (port); |
188 | |
189 | *addr = val; |
190 | __ia64_mf_a(); |
191 | } |
192 | |
193 | weak_alias (_ioperm, ioperm); |
194 | weak_alias (_iopl, iopl); |
195 | weak_alias (_inb, inb); |
196 | weak_alias (_inw, inw); |
197 | weak_alias (_inl, inl); |
198 | weak_alias (_outb, outb); |
199 | weak_alias (_outw, outw); |
200 | weak_alias (_outl, outl); |
201 | |