Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * proc_devtree.c - handles /proc/device-tree | |
3 | * | |
4 | * Copyright 1997 Paul Mackerras | |
5 | */ | |
6 | #include <linux/errno.h> | |
7 | #include <linux/time.h> | |
8 | #include <linux/proc_fs.h> | |
9 | #include <linux/stat.h> | |
10 | #include <linux/string.h> | |
11 | #include <asm/prom.h> | |
12 | #include <asm/uaccess.h> | |
13 | ||
14 | #ifndef HAVE_ARCH_DEVTREE_FIXUPS | |
5f64f739 BH |
15 | static inline void set_node_proc_entry(struct device_node *np, |
16 | struct proc_dir_entry *de) | |
1da177e4 LT |
17 | { |
18 | } | |
19 | #endif | |
20 | ||
21 | static struct proc_dir_entry *proc_device_tree; | |
22 | ||
23 | /* | |
24 | * Supply data on a read from /proc/device-tree/node/property. | |
25 | */ | |
26 | static int property_read_proc(char *page, char **start, off_t off, | |
27 | int count, int *eof, void *data) | |
28 | { | |
29 | struct property *pp = data; | |
30 | int n; | |
31 | ||
32 | if (off >= pp->length) { | |
33 | *eof = 1; | |
34 | return 0; | |
35 | } | |
36 | n = pp->length - off; | |
37 | if (n > count) | |
38 | n = count; | |
39 | else | |
40 | *eof = 1; | |
1a38147e | 41 | memcpy(page, (char *)pp->value + off, n); |
1da177e4 LT |
42 | *start = page; |
43 | return n; | |
44 | } | |
45 | ||
46 | /* | |
47 | * For a node with a name like "gc@10", we make symlinks called "gc" | |
48 | * and "@10" to it. | |
49 | */ | |
50 | ||
183d0202 BH |
51 | /* |
52 | * Add a property to a node | |
53 | */ | |
54 | static struct proc_dir_entry * | |
5149fa47 ME |
55 | __proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp, |
56 | const char *name) | |
183d0202 BH |
57 | { |
58 | struct proc_dir_entry *ent; | |
59 | ||
60 | /* | |
61 | * Unfortunately proc_register puts each new entry | |
62 | * at the beginning of the list. So we rearrange them. | |
63 | */ | |
5149fa47 ME |
64 | ent = create_proc_read_entry(name, |
65 | strncmp(name, "security-", 9) | |
183d0202 BH |
66 | ? S_IRUGO : S_IRUSR, de, |
67 | property_read_proc, pp); | |
68 | if (ent == NULL) | |
69 | return NULL; | |
70 | ||
5149fa47 | 71 | if (!strncmp(name, "security-", 9)) |
183d0202 BH |
72 | ent->size = 0; /* don't leak number of password chars */ |
73 | else | |
74 | ent->size = pp->length; | |
75 | ||
76 | return ent; | |
77 | } | |
78 | ||
79 | ||
80 | void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop) | |
81 | { | |
5149fa47 | 82 | __proc_device_tree_add_prop(pde, prop, prop->name); |
183d0202 BH |
83 | } |
84 | ||
898b5395 DB |
85 | void proc_device_tree_remove_prop(struct proc_dir_entry *pde, |
86 | struct property *prop) | |
87 | { | |
88 | remove_proc_entry(prop->name, pde); | |
89 | } | |
90 | ||
91 | void proc_device_tree_update_prop(struct proc_dir_entry *pde, | |
92 | struct property *newprop, | |
93 | struct property *oldprop) | |
94 | { | |
95 | struct proc_dir_entry *ent; | |
96 | ||
97 | for (ent = pde->subdir; ent != NULL; ent = ent->next) | |
98 | if (ent->data == oldprop) | |
99 | break; | |
100 | if (ent == NULL) { | |
101 | printk(KERN_WARNING "device-tree: property \"%s\" " | |
102 | " does not exist\n", oldprop->name); | |
103 | } else { | |
104 | ent->data = newprop; | |
105 | ent->size = newprop->length; | |
106 | } | |
107 | } | |
108 | ||
5149fa47 ME |
109 | /* |
110 | * Various dodgy firmware might give us nodes and/or properties with | |
111 | * conflicting names. That's generally ok, except for exporting via /proc, | |
112 | * so munge names here to ensure they're unique. | |
113 | */ | |
114 | ||
115 | static int duplicate_name(struct proc_dir_entry *de, const char *name) | |
116 | { | |
117 | struct proc_dir_entry *ent; | |
118 | int found = 0; | |
119 | ||
120 | spin_lock(&proc_subdir_lock); | |
121 | ||
122 | for (ent = de->subdir; ent != NULL; ent = ent->next) { | |
123 | if (strcmp(ent->name, name) == 0) { | |
124 | found = 1; | |
125 | break; | |
126 | } | |
127 | } | |
128 | ||
129 | spin_unlock(&proc_subdir_lock); | |
130 | ||
131 | return found; | |
132 | } | |
133 | ||
134 | static const char *fixup_name(struct device_node *np, struct proc_dir_entry *de, | |
135 | const char *name) | |
136 | { | |
137 | char *fixed_name; | |
138 | int fixup_len = strlen(name) + 2 + 1; /* name + #x + \0 */ | |
139 | int i = 1, size; | |
140 | ||
141 | realloc: | |
142 | fixed_name = kmalloc(fixup_len, GFP_KERNEL); | |
143 | if (fixed_name == NULL) { | |
144 | printk(KERN_ERR "device-tree: Out of memory trying to fixup " | |
145 | "name \"%s\"\n", name); | |
146 | return name; | |
147 | } | |
148 | ||
149 | retry: | |
150 | size = snprintf(fixed_name, fixup_len, "%s#%d", name, i); | |
151 | size++; /* account for NULL */ | |
152 | ||
153 | if (size > fixup_len) { | |
154 | /* We ran out of space, free and reallocate. */ | |
155 | kfree(fixed_name); | |
156 | fixup_len = size; | |
157 | goto realloc; | |
158 | } | |
159 | ||
160 | if (duplicate_name(de, fixed_name)) { | |
161 | /* Multiple duplicates. Retry with a different offset. */ | |
162 | i++; | |
163 | goto retry; | |
164 | } | |
165 | ||
166 | printk(KERN_WARNING "device-tree: Duplicate name in %s, " | |
167 | "renamed to \"%s\"\n", np->full_name, fixed_name); | |
168 | ||
169 | return fixed_name; | |
170 | } | |
171 | ||
1da177e4 LT |
172 | /* |
173 | * Process a node, adding entries for its children and its properties. | |
174 | */ | |
5f64f739 BH |
175 | void proc_device_tree_add_node(struct device_node *np, |
176 | struct proc_dir_entry *de) | |
1da177e4 LT |
177 | { |
178 | struct property *pp; | |
179 | struct proc_dir_entry *ent; | |
5f64f739 | 180 | struct device_node *child; |
5f64f739 | 181 | const char *p; |
1da177e4 LT |
182 | |
183 | set_node_proc_entry(np, de); | |
5f64f739 | 184 | for (child = NULL; (child = of_get_next_child(np, child));) { |
5149fa47 | 185 | /* Use everything after the last slash, or the full name */ |
1da177e4 LT |
186 | p = strrchr(child->full_name, '/'); |
187 | if (!p) | |
188 | p = child->full_name; | |
189 | else | |
190 | ++p; | |
5149fa47 ME |
191 | |
192 | if (duplicate_name(de, p)) | |
193 | p = fixup_name(np, de, p); | |
194 | ||
1da177e4 LT |
195 | ent = proc_mkdir(p, de); |
196 | if (ent == 0) | |
197 | break; | |
1da177e4 | 198 | proc_device_tree_add_node(child, ent); |
5f64f739 BH |
199 | } |
200 | of_node_put(child); | |
5149fa47 | 201 | |
5f64f739 | 202 | for (pp = np->properties; pp != 0; pp = pp->next) { |
5149fa47 ME |
203 | p = pp->name; |
204 | ||
205 | if (duplicate_name(de, p)) | |
206 | p = fixup_name(np, de, p); | |
5f64f739 | 207 | |
5149fa47 | 208 | ent = __proc_device_tree_add_prop(de, pp, p); |
5f64f739 | 209 | if (ent == 0) |
1da177e4 | 210 | break; |
1da177e4 | 211 | } |
1da177e4 LT |
212 | } |
213 | ||
214 | /* | |
215 | * Called on initialization to set up the /proc/device-tree subtree | |
216 | */ | |
217 | void proc_device_tree_init(void) | |
218 | { | |
219 | struct device_node *root; | |
220 | if ( !have_of ) | |
221 | return; | |
222 | proc_device_tree = proc_mkdir("device-tree", NULL); | |
223 | if (proc_device_tree == 0) | |
224 | return; | |
225 | root = of_find_node_by_path("/"); | |
226 | if (root == 0) { | |
227 | printk(KERN_ERR "/proc/device-tree: can't find root\n"); | |
228 | return; | |
229 | } | |
230 | proc_device_tree_add_node(root, proc_device_tree); | |
231 | of_node_put(root); | |
232 | } |