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31#include <linux/kernel.h>
32#include <linux/gfp.h>
33#include <linux/module.h>
34#include <linux/init.h>
35#include <linux/proc_fs.h>
36#include <linux/seq_file.h>
37#include <asm/console.h>
38#include <linux/uaccess.h>
39#include <asm/machvec.h>
40
41#define BASE_DIR "srm_environment"
42#define NAMED_DIR "named_variables"
43#define NUMBERED_DIR "numbered_variables"
44#define VERSION "0.0.6"
45#define NAME "srm_env"
46
47MODULE_AUTHOR("Jan-Benedict Glaw <jbglaw@lug-owl.de>");
48MODULE_DESCRIPTION("Accessing Alpha SRM environment through procfs interface");
49MODULE_LICENSE("GPL");
50
51typedef struct _srm_env {
52 char *name;
53 unsigned long id;
54} srm_env_t;
55
56static struct proc_dir_entry *base_dir;
57static struct proc_dir_entry *named_dir;
58static struct proc_dir_entry *numbered_dir;
59
60static srm_env_t srm_named_entries[] = {
61 { "auto_action", ENV_AUTO_ACTION },
62 { "boot_dev", ENV_BOOT_DEV },
63 { "bootdef_dev", ENV_BOOTDEF_DEV },
64 { "booted_dev", ENV_BOOTED_DEV },
65 { "boot_file", ENV_BOOT_FILE },
66 { "booted_file", ENV_BOOTED_FILE },
67 { "boot_osflags", ENV_BOOT_OSFLAGS },
68 { "booted_osflags", ENV_BOOTED_OSFLAGS },
69 { "boot_reset", ENV_BOOT_RESET },
70 { "dump_dev", ENV_DUMP_DEV },
71 { "enable_audit", ENV_ENABLE_AUDIT },
72 { "license", ENV_LICENSE },
73 { "char_set", ENV_CHAR_SET },
74 { "language", ENV_LANGUAGE },
75 { "tty_dev", ENV_TTY_DEV },
76 { NULL, 0 },
77};
78
79static int srm_env_proc_show(struct seq_file *m, void *v)
80{
81 unsigned long ret;
82 unsigned long id = (unsigned long)m->private;
83 char *page;
84
85 page = (char *)__get_free_page(GFP_USER);
86 if (!page)
87 return -ENOMEM;
88
89 ret = callback_getenv(id, page, PAGE_SIZE);
90
91 if ((ret >> 61) == 0) {
92 seq_write(m, page, ret);
93 ret = 0;
94 } else
95 ret = -EFAULT;
96 free_page((unsigned long)page);
97 return ret;
98}
99
100static int srm_env_proc_open(struct inode *inode, struct file *file)
101{
102 return single_open(file, srm_env_proc_show, PDE_DATA(inode));
103}
104
105static ssize_t srm_env_proc_write(struct file *file, const char __user *buffer,
106 size_t count, loff_t *pos)
107{
108 int res;
109 unsigned long id = (unsigned long)PDE_DATA(file_inode(file));
110 char *buf = (char *) __get_free_page(GFP_USER);
111 unsigned long ret1, ret2;
112
113 if (!buf)
114 return -ENOMEM;
115
116 res = -EINVAL;
117 if (count >= PAGE_SIZE)
118 goto out;
119
120 res = -EFAULT;
121 if (copy_from_user(buf, buffer, count))
122 goto out;
123 buf[count] = '\0';
124
125 ret1 = callback_setenv(id, buf, count);
126 if ((ret1 >> 61) == 0) {
127 do
128 ret2 = callback_save_env();
129 while((ret2 >> 61) == 1);
130 res = (int) ret1;
131 }
132
133 out:
134 free_page((unsigned long)buf);
135 return res;
136}
137
138static const struct file_operations srm_env_proc_fops = {
139 .owner = THIS_MODULE,
140 .open = srm_env_proc_open,
141 .read = seq_read,
142 .llseek = seq_lseek,
143 .release = single_release,
144 .write = srm_env_proc_write,
145};
146
147static int __init
148srm_env_init(void)
149{
150 srm_env_t *entry;
151 unsigned long var_num;
152
153
154
155
156 if (!alpha_using_srm) {
157 printk(KERN_INFO "%s: This Alpha system doesn't "
158 "know about SRM (or you've booted "
159 "SRM->MILO->Linux, which gets "
160 "misdetected)...\n", __func__);
161 return -ENODEV;
162 }
163
164
165
166
167 base_dir = proc_mkdir(BASE_DIR, NULL);
168 if (!base_dir) {
169 printk(KERN_ERR "Couldn't create base dir /proc/%s\n",
170 BASE_DIR);
171 return -ENOMEM;
172 }
173
174
175
176
177 named_dir = proc_mkdir(NAMED_DIR, base_dir);
178 if (!named_dir) {
179 printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n",
180 BASE_DIR, NAMED_DIR);
181 goto cleanup;
182 }
183
184
185
186
187 numbered_dir = proc_mkdir(NUMBERED_DIR, base_dir);
188 if (!numbered_dir) {
189 printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n",
190 BASE_DIR, NUMBERED_DIR);
191 goto cleanup;
192
193 }
194
195
196
197
198 entry = srm_named_entries;
199 while (entry->name && entry->id) {
200 if (!proc_create_data(entry->name, 0644, named_dir,
201 &srm_env_proc_fops, (void *)entry->id))
202 goto cleanup;
203 entry++;
204 }
205
206
207
208
209 for (var_num = 0; var_num <= 255; var_num++) {
210 char name[4];
211 sprintf(name, "%ld", var_num);
212 if (!proc_create_data(name, 0644, numbered_dir,
213 &srm_env_proc_fops, (void *)var_num))
214 goto cleanup;
215 }
216
217 printk(KERN_INFO "%s: version %s loaded successfully\n", NAME,
218 VERSION);
219
220 return 0;
221
222cleanup:
223 remove_proc_subtree(BASE_DIR, NULL);
224 return -ENOMEM;
225}
226
227static void __exit
228srm_env_exit(void)
229{
230 remove_proc_subtree(BASE_DIR, NULL);
231 printk(KERN_INFO "%s: unloaded successfully\n", NAME);
232}
233
234module_init(srm_env_init);
235module_exit(srm_env_exit);
236