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-rw-r--r--Documentation/ia64/aliasing-test.c247
1 files changed, 247 insertions, 0 deletions
diff --git a/Documentation/ia64/aliasing-test.c b/Documentation/ia64/aliasing-test.c
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1/*
2 * Exercise /dev/mem mmap cases that have been troublesome in the past
3 *
4 * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
5 * Bjorn Helgaas <bjorn.helgaas@hp.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <stdlib.h>
13#include <stdio.h>
14#include <sys/types.h>
15#include <dirent.h>
16#include <fcntl.h>
17#include <fnmatch.h>
18#include <string.h>
19#include <sys/mman.h>
20#include <sys/stat.h>
21#include <unistd.h>
22
23int sum;
24
25int map_mem(char *path, off_t offset, size_t length, int touch)
26{
27 int fd, rc;
28 void *addr;
29 int *c;
30
31 fd = open(path, O_RDWR);
32 if (fd == -1) {
33 perror(path);
34 return -1;
35 }
36
37 addr = mmap(NULL, length, PROT_READ|PROT_WRITE, MAP_SHARED, fd, offset);
38 if (addr == MAP_FAILED)
39 return 1;
40
41 if (touch) {
42 c = (int *) addr;
43 while (c < (int *) (offset + length))
44 sum += *c++;
45 }
46
47 rc = munmap(addr, length);
48 if (rc == -1) {
49 perror("munmap");
50 return -1;
51 }
52
53 close(fd);
54 return 0;
55}
56
57int scan_sysfs(char *path, char *file, off_t offset, size_t length, int touch)
58{
59 struct dirent **namelist;
60 char *name, *path2;
61 int i, n, r, rc, result = 0;
62 struct stat buf;
63
64 n = scandir(path, &namelist, 0, alphasort);
65 if (n < 0) {
66 perror("scandir");
67 return -1;
68 }
69
70 for (i = 0; i < n; i++) {
71 name = namelist[i]->d_name;
72
73 if (fnmatch(".", name, 0) == 0)
74 goto skip;
75 if (fnmatch("..", name, 0) == 0)
76 goto skip;
77
78 path2 = malloc(strlen(path) + strlen(name) + 3);
79 strcpy(path2, path);
80 strcat(path2, "/");
81 strcat(path2, name);
82
83 if (fnmatch(file, name, 0) == 0) {
84 rc = map_mem(path2, offset, length, touch);
85 if (rc == 0)
86 fprintf(stderr, "PASS: %s 0x%lx-0x%lx is %s\n", path2, offset, offset + length, touch ? "readable" : "mappable");
87 else if (rc > 0)
88 fprintf(stderr, "PASS: %s 0x%lx-0x%lx not mappable\n", path2, offset, offset + length);
89 else {
90 fprintf(stderr, "FAIL: %s 0x%lx-0x%lx not accessible\n", path2, offset, offset + length);
91 return rc;
92 }
93 } else {
94 r = lstat(path2, &buf);
95 if (r == 0 && S_ISDIR(buf.st_mode)) {
96 rc = scan_sysfs(path2, file, offset, length, touch);
97 if (rc < 0)
98 return rc;
99 }
100 }
101
102 result |= rc;
103 free(path2);
104
105skip:
106 free(namelist[i]);
107 }
108 free(namelist);
109 return rc;
110}
111
112char buf[1024];
113
114int read_rom(char *path)
115{
116 int fd, rc;
117 size_t size = 0;
118
119 fd = open(path, O_RDWR);
120 if (fd == -1) {
121 perror(path);
122 return -1;
123 }
124
125 rc = write(fd, "1", 2);
126 if (rc <= 0) {
127 perror("write");
128 return -1;
129 }
130
131 do {
132 rc = read(fd, buf, sizeof(buf));
133 if (rc > 0)
134 size += rc;
135 } while (rc > 0);
136
137 close(fd);
138 return size;
139}
140
141int scan_rom(char *path, char *file)
142{
143 struct dirent **namelist;
144 char *name, *path2;
145 int i, n, r, rc, result = 0;
146 struct stat buf;
147
148 n = scandir(path, &namelist, 0, alphasort);
149 if (n < 0) {
150 perror("scandir");
151 return -1;
152 }
153
154 for (i = 0; i < n; i++) {
155 name = namelist[i]->d_name;
156
157 if (fnmatch(".", name, 0) == 0)
158 goto skip;
159 if (fnmatch("..", name, 0) == 0)
160 goto skip;
161
162 path2 = malloc(strlen(path) + strlen(name) + 3);
163 strcpy(path2, path);
164 strcat(path2, "/");
165 strcat(path2, name);
166
167 if (fnmatch(file, name, 0) == 0) {
168 rc = read_rom(path2);
169
170 /*
171 * It's OK if the ROM is unreadable. Maybe there
172 * is no ROM, or some other error ocurred. The
173 * important thing is that no MCA happened.
174 */
175 if (rc > 0)
176 fprintf(stderr, "PASS: %s read %ld bytes\n", path2, rc);
177 else {
178 fprintf(stderr, "PASS: %s not readable\n", path2);
179 return rc;
180 }
181 } else {
182 r = lstat(path2, &buf);
183 if (r == 0 && S_ISDIR(buf.st_mode)) {
184 rc = scan_rom(path2, file);
185 if (rc < 0)
186 return rc;
187 }
188 }
189
190 result |= rc;
191 free(path2);
192
193skip:
194 free(namelist[i]);
195 }
196 free(namelist);
197 return rc;
198}
199
200main()
201{
202 int rc;
203
204 if (map_mem("/dev/mem", 0, 0xA0000, 1) == 0)
205 fprintf(stderr, "PASS: /dev/mem 0x0-0xa0000 is readable\n");
206 else
207 fprintf(stderr, "FAIL: /dev/mem 0x0-0xa0000 not accessible\n");
208
209 /*
210 * It's not safe to blindly read the VGA frame buffer. If you know
211 * how to poke the card the right way, it should respond, but it's
212 * not safe in general. Many machines, e.g., Intel chipsets, cover
213 * up a non-responding card by just returning -1, but others will
214 * report the failure as a machine check.
215 */
216 if (map_mem("/dev/mem", 0xA0000, 0x20000, 0) == 0)
217 fprintf(stderr, "PASS: /dev/mem 0xa0000-0xc0000 is mappable\n");
218 else
219 fprintf(stderr, "FAIL: /dev/mem 0xa0000-0xc0000 not accessible\n");
220
221 if (map_mem("/dev/mem", 0xC0000, 0x40000, 1) == 0)
222 fprintf(stderr, "PASS: /dev/mem 0xc0000-0x100000 is readable\n");
223 else
224 fprintf(stderr, "FAIL: /dev/mem 0xc0000-0x100000 not accessible\n");
225
226 /*
227 * Often you can map all the individual pieces above (0-0xA0000,
228 * 0xA0000-0xC0000, and 0xC0000-0x100000), but can't map the whole
229 * thing at once. This is because the individual pieces use different
230 * attributes, and there's no single attribute supported over the
231 * whole region.
232 */
233 rc = map_mem("/dev/mem", 0, 1024*1024, 0);
234 if (rc == 0)
235 fprintf(stderr, "PASS: /dev/mem 0x0-0x100000 is mappable\n");
236 else if (rc > 0)
237 fprintf(stderr, "PASS: /dev/mem 0x0-0x100000 not mappable\n");
238 else
239 fprintf(stderr, "FAIL: /dev/mem 0x0-0x100000 not accessible\n");
240
241 scan_sysfs("/sys/class/pci_bus", "legacy_mem", 0, 0xA0000, 1);
242 scan_sysfs("/sys/class/pci_bus", "legacy_mem", 0xA0000, 0x20000, 0);
243 scan_sysfs("/sys/class/pci_bus", "legacy_mem", 0xC0000, 0x40000, 1);
244 scan_sysfs("/sys/class/pci_bus", "legacy_mem", 0, 1024*1024, 0);
245
246 scan_rom("/sys/devices", "rom");
247}
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