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1da177e4 LT |
1 | /* |
2 | * srm_env.c - Access to SRM environment | |
3 | * variables through linux' procfs | |
4 | * | |
5 | * Copyright (C) 2001-2002 Jan-Benedict Glaw <jbglaw@lug-owl.de> | |
6 | * | |
7 | * This driver is at all a modified version of Erik Mouw's | |
8 | * Documentation/DocBook/procfs_example.c, so: thank | |
9 | * you, Erik! He can be reached via email at | |
10 | * <J.A.K.Mouw@its.tudelft.nl>. It is based on an idea | |
11 | * provided by DEC^WCompaq^WIntel's "Jumpstart" CD. They | |
12 | * included a patch like this as well. Thanks for idea! | |
13 | * | |
14 | * This program is free software; you can redistribute | |
15 | * it and/or modify it under the terms of the GNU General | |
16 | * Public License version 2 as published by the Free Software | |
17 | * Foundation. | |
18 | * | |
19 | * This program is distributed in the hope that it will be | |
20 | * useful, but WITHOUT ANY WARRANTY; without even the implied | |
21 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR | |
22 | * PURPOSE. See the GNU General Public License for more | |
23 | * details. | |
24 | * | |
25 | * You should have received a copy of the GNU General Public | |
26 | * License along with this program; if not, write to the | |
27 | * Free Software Foundation, Inc., 59 Temple Place, | |
28 | * Suite 330, Boston, MA 02111-1307 USA | |
29 | * | |
30 | */ | |
31 | ||
32 | /* | |
33 | * Changelog | |
34 | * ~~~~~~~~~ | |
35 | * | |
36 | * Thu, 22 Aug 2002 15:10:43 +0200 | |
37 | * - Update Config.help entry. I got a number of emails asking | |
38 | * me to tell their senders if they could make use of this | |
39 | * piece of code... So: "SRM is something like BIOS for your | |
40 | * Alpha" | |
41 | * - Update code formatting a bit to better conform CodingStyle | |
42 | * rules. | |
43 | * - So this is v0.0.5, with no changes (except formatting) | |
44 | * | |
45 | * Wed, 22 May 2002 00:11:21 +0200 | |
46 | * - Fix typo on comment (SRC -> SRM) | |
47 | * - Call this "Version 0.0.4" | |
48 | * | |
49 | * Tue, 9 Apr 2002 18:44:40 +0200 | |
50 | * - Implement access by variable name and additionally | |
51 | * by number. This is done by creating two subdirectories | |
52 | * where one holds all names (like the old directory | |
53 | * did) and the other holding 256 files named like "0", | |
54 | * "1" and so on. | |
55 | * - Call this "Version 0.0.3" | |
56 | * | |
57 | */ | |
58 | ||
59 | #include <linux/kernel.h> | |
60 | #include <linux/config.h> | |
61 | #include <linux/module.h> | |
62 | #include <linux/init.h> | |
63 | #include <linux/proc_fs.h> | |
64 | #include <asm/console.h> | |
65 | #include <asm/uaccess.h> | |
66 | #include <asm/machvec.h> | |
67 | ||
68 | #define BASE_DIR "srm_environment" /* Subdir in /proc/ */ | |
69 | #define NAMED_DIR "named_variables" /* Subdir for known variables */ | |
70 | #define NUMBERED_DIR "numbered_variables" /* Subdir for all variables */ | |
71 | #define VERSION "0.0.5" /* Module version */ | |
72 | #define NAME "srm_env" /* Module name */ | |
73 | ||
74 | MODULE_AUTHOR("Jan-Benedict Glaw <jbglaw@lug-owl.de>"); | |
75 | MODULE_DESCRIPTION("Accessing Alpha SRM environment through procfs interface"); | |
76 | MODULE_LICENSE("GPL"); | |
77 | ||
78 | typedef struct _srm_env { | |
79 | char *name; | |
80 | unsigned long id; | |
81 | struct proc_dir_entry *proc_entry; | |
82 | } srm_env_t; | |
83 | ||
84 | static struct proc_dir_entry *base_dir; | |
85 | static struct proc_dir_entry *named_dir; | |
86 | static struct proc_dir_entry *numbered_dir; | |
87 | static char number[256][4]; | |
88 | ||
89 | static srm_env_t srm_named_entries[] = { | |
90 | { "auto_action", ENV_AUTO_ACTION }, | |
91 | { "boot_dev", ENV_BOOT_DEV }, | |
92 | { "bootdef_dev", ENV_BOOTDEF_DEV }, | |
93 | { "booted_dev", ENV_BOOTED_DEV }, | |
94 | { "boot_file", ENV_BOOT_FILE }, | |
95 | { "booted_file", ENV_BOOTED_FILE }, | |
96 | { "boot_osflags", ENV_BOOT_OSFLAGS }, | |
97 | { "booted_osflags", ENV_BOOTED_OSFLAGS }, | |
98 | { "boot_reset", ENV_BOOT_RESET }, | |
99 | { "dump_dev", ENV_DUMP_DEV }, | |
100 | { "enable_audit", ENV_ENABLE_AUDIT }, | |
101 | { "license", ENV_LICENSE }, | |
102 | { "char_set", ENV_CHAR_SET }, | |
103 | { "language", ENV_LANGUAGE }, | |
104 | { "tty_dev", ENV_TTY_DEV }, | |
105 | { NULL, 0 }, | |
106 | }; | |
107 | static srm_env_t srm_numbered_entries[256]; | |
108 | ||
109 | ||
110 | ||
111 | static int | |
112 | srm_env_read(char *page, char **start, off_t off, int count, int *eof, | |
113 | void *data) | |
114 | { | |
115 | int nbytes; | |
116 | unsigned long ret; | |
117 | srm_env_t *entry; | |
118 | ||
119 | if(off != 0) | |
120 | return -EFAULT; | |
121 | ||
122 | entry = (srm_env_t *) data; | |
123 | ret = callback_getenv(entry->id, page, count); | |
124 | ||
125 | if((ret >> 61) == 0) | |
126 | nbytes = (int) ret; | |
127 | else | |
128 | nbytes = -EFAULT; | |
129 | ||
130 | return nbytes; | |
131 | } | |
132 | ||
133 | ||
134 | static int | |
135 | srm_env_write(struct file *file, const char __user *buffer, unsigned long count, | |
136 | void *data) | |
137 | { | |
138 | int res; | |
139 | srm_env_t *entry; | |
140 | char *buf = (char *) __get_free_page(GFP_USER); | |
141 | unsigned long ret1, ret2; | |
142 | ||
143 | entry = (srm_env_t *) data; | |
144 | ||
145 | if (!buf) | |
146 | return -ENOMEM; | |
147 | ||
148 | res = -EINVAL; | |
149 | if (count >= PAGE_SIZE) | |
150 | goto out; | |
151 | ||
152 | res = -EFAULT; | |
153 | if (copy_from_user(buf, buffer, count)) | |
154 | goto out; | |
155 | buf[count] = '\0'; | |
156 | ||
157 | ret1 = callback_setenv(entry->id, buf, count); | |
158 | if ((ret1 >> 61) == 0) { | |
159 | do | |
160 | ret2 = callback_save_env(); | |
161 | while((ret2 >> 61) == 1); | |
162 | res = (int) ret1; | |
163 | } | |
164 | ||
165 | out: | |
166 | free_page((unsigned long)buf); | |
167 | return res; | |
168 | } | |
169 | ||
170 | static void | |
171 | srm_env_cleanup(void) | |
172 | { | |
173 | srm_env_t *entry; | |
174 | unsigned long var_num; | |
175 | ||
176 | if(base_dir) { | |
177 | /* | |
178 | * Remove named entries | |
179 | */ | |
180 | if(named_dir) { | |
181 | entry = srm_named_entries; | |
182 | while(entry->name != NULL && entry->id != 0) { | |
183 | if(entry->proc_entry) { | |
184 | remove_proc_entry(entry->name, | |
185 | named_dir); | |
186 | entry->proc_entry = NULL; | |
187 | } | |
188 | entry++; | |
189 | } | |
190 | remove_proc_entry(NAMED_DIR, base_dir); | |
191 | } | |
192 | ||
193 | /* | |
194 | * Remove numbered entries | |
195 | */ | |
196 | if(numbered_dir) { | |
197 | for(var_num = 0; var_num <= 255; var_num++) { | |
198 | entry = &srm_numbered_entries[var_num]; | |
199 | ||
200 | if(entry->proc_entry) { | |
201 | remove_proc_entry(entry->name, | |
202 | numbered_dir); | |
203 | entry->proc_entry = NULL; | |
204 | entry->name = NULL; | |
205 | } | |
206 | } | |
207 | remove_proc_entry(NUMBERED_DIR, base_dir); | |
208 | } | |
209 | ||
210 | remove_proc_entry(BASE_DIR, NULL); | |
211 | } | |
212 | ||
213 | return; | |
214 | } | |
215 | ||
216 | ||
217 | static int __init | |
218 | srm_env_init(void) | |
219 | { | |
220 | srm_env_t *entry; | |
221 | unsigned long var_num; | |
222 | ||
223 | /* | |
224 | * Check system | |
225 | */ | |
226 | if(!alpha_using_srm) { | |
227 | printk(KERN_INFO "%s: This Alpha system doesn't " | |
228 | "know about SRM (or you've booted " | |
229 | "SRM->MILO->Linux, which gets " | |
230 | "misdetected)...\n", __FUNCTION__); | |
231 | return -ENODEV; | |
232 | } | |
233 | ||
234 | /* | |
235 | * Init numbers | |
236 | */ | |
237 | for(var_num = 0; var_num <= 255; var_num++) | |
238 | sprintf(number[var_num], "%ld", var_num); | |
239 | ||
240 | /* | |
241 | * Create base directory | |
242 | */ | |
243 | base_dir = proc_mkdir(BASE_DIR, NULL); | |
244 | if(base_dir == NULL) { | |
245 | printk(KERN_ERR "Couldn't create base dir /proc/%s\n", | |
246 | BASE_DIR); | |
247 | goto cleanup; | |
248 | } | |
249 | base_dir->owner = THIS_MODULE; | |
250 | ||
251 | /* | |
252 | * Create per-name subdirectory | |
253 | */ | |
254 | named_dir = proc_mkdir(NAMED_DIR, base_dir); | |
255 | if(named_dir == NULL) { | |
256 | printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n", | |
257 | BASE_DIR, NAMED_DIR); | |
258 | goto cleanup; | |
259 | } | |
260 | named_dir->owner = THIS_MODULE; | |
261 | ||
262 | /* | |
263 | * Create per-number subdirectory | |
264 | */ | |
265 | numbered_dir = proc_mkdir(NUMBERED_DIR, base_dir); | |
266 | if(numbered_dir == NULL) { | |
267 | printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n", | |
268 | BASE_DIR, NUMBERED_DIR); | |
269 | goto cleanup; | |
270 | ||
271 | } | |
272 | numbered_dir->owner = THIS_MODULE; | |
273 | ||
274 | /* | |
275 | * Create all named nodes | |
276 | */ | |
277 | entry = srm_named_entries; | |
278 | while(entry->name != NULL && entry->id != 0) { | |
279 | entry->proc_entry = create_proc_entry(entry->name, | |
280 | 0644, named_dir); | |
281 | if(entry->proc_entry == NULL) | |
282 | goto cleanup; | |
283 | ||
284 | entry->proc_entry->data = (void *) entry; | |
285 | entry->proc_entry->owner = THIS_MODULE; | |
286 | entry->proc_entry->read_proc = srm_env_read; | |
287 | entry->proc_entry->write_proc = srm_env_write; | |
288 | ||
289 | entry++; | |
290 | } | |
291 | ||
292 | /* | |
293 | * Create all numbered nodes | |
294 | */ | |
295 | for(var_num = 0; var_num <= 255; var_num++) { | |
296 | entry = &srm_numbered_entries[var_num]; | |
297 | entry->name = number[var_num]; | |
298 | ||
299 | entry->proc_entry = create_proc_entry(entry->name, | |
300 | 0644, numbered_dir); | |
301 | if(entry->proc_entry == NULL) | |
302 | goto cleanup; | |
303 | ||
304 | entry->id = var_num; | |
305 | entry->proc_entry->data = (void *) entry; | |
306 | entry->proc_entry->owner = THIS_MODULE; | |
307 | entry->proc_entry->read_proc = srm_env_read; | |
308 | entry->proc_entry->write_proc = srm_env_write; | |
309 | } | |
310 | ||
311 | printk(KERN_INFO "%s: version %s loaded successfully\n", NAME, | |
312 | VERSION); | |
313 | ||
314 | return 0; | |
315 | ||
316 | cleanup: | |
317 | srm_env_cleanup(); | |
318 | ||
319 | return -ENOMEM; | |
320 | } | |
321 | ||
322 | ||
323 | static void __exit | |
324 | srm_env_exit(void) | |
325 | { | |
326 | srm_env_cleanup(); | |
327 | printk(KERN_INFO "%s: unloaded successfully\n", NAME); | |
328 | ||
329 | return; | |
330 | } | |
331 | ||
332 | ||
333 | module_init(srm_env_init); | |
334 | module_exit(srm_env_exit); | |
335 |