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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> | |
1e0edd3f | 7 | #include <linux/init.h> |
1da177e4 LT |
8 | #include <linux/time.h> |
9 | #include <linux/proc_fs.h> | |
10 | #include <linux/stat.h> | |
11 | #include <linux/string.h> | |
12 | #include <asm/prom.h> | |
13 | #include <asm/uaccess.h> | |
3174c21b | 14 | #include "internal.h" |
1da177e4 LT |
15 | |
16 | #ifndef HAVE_ARCH_DEVTREE_FIXUPS | |
5f64f739 BH |
17 | static inline void set_node_proc_entry(struct device_node *np, |
18 | struct proc_dir_entry *de) | |
1da177e4 LT |
19 | { |
20 | } | |
21 | #endif | |
22 | ||
23 | static struct proc_dir_entry *proc_device_tree; | |
24 | ||
25 | /* | |
26 | * Supply data on a read from /proc/device-tree/node/property. | |
27 | */ | |
28 | static int property_read_proc(char *page, char **start, off_t off, | |
29 | int count, int *eof, void *data) | |
30 | { | |
31 | struct property *pp = data; | |
32 | int n; | |
33 | ||
34 | if (off >= pp->length) { | |
35 | *eof = 1; | |
36 | return 0; | |
37 | } | |
38 | n = pp->length - off; | |
39 | if (n > count) | |
40 | n = count; | |
41 | else | |
42 | *eof = 1; | |
1a38147e | 43 | memcpy(page, (char *)pp->value + off, n); |
1da177e4 LT |
44 | *start = page; |
45 | return n; | |
46 | } | |
47 | ||
48 | /* | |
49 | * For a node with a name like "gc@10", we make symlinks called "gc" | |
50 | * and "@10" to it. | |
51 | */ | |
52 | ||
183d0202 BH |
53 | /* |
54 | * Add a property to a node | |
55 | */ | |
56 | static struct proc_dir_entry * | |
5149fa47 ME |
57 | __proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp, |
58 | const char *name) | |
183d0202 BH |
59 | { |
60 | struct proc_dir_entry *ent; | |
61 | ||
62 | /* | |
63 | * Unfortunately proc_register puts each new entry | |
64 | * at the beginning of the list. So we rearrange them. | |
65 | */ | |
5149fa47 ME |
66 | ent = create_proc_read_entry(name, |
67 | strncmp(name, "security-", 9) | |
183d0202 BH |
68 | ? S_IRUGO : S_IRUSR, de, |
69 | property_read_proc, pp); | |
70 | if (ent == NULL) | |
71 | return NULL; | |
72 | ||
5149fa47 | 73 | if (!strncmp(name, "security-", 9)) |
183d0202 BH |
74 | ent->size = 0; /* don't leak number of password chars */ |
75 | else | |
76 | ent->size = pp->length; | |
77 | ||
78 | return ent; | |
79 | } | |
80 | ||
81 | ||
82 | void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop) | |
83 | { | |
5149fa47 | 84 | __proc_device_tree_add_prop(pde, prop, prop->name); |
183d0202 BH |
85 | } |
86 | ||
898b5395 DB |
87 | void proc_device_tree_remove_prop(struct proc_dir_entry *pde, |
88 | struct property *prop) | |
89 | { | |
90 | remove_proc_entry(prop->name, pde); | |
91 | } | |
92 | ||
93 | void proc_device_tree_update_prop(struct proc_dir_entry *pde, | |
94 | struct property *newprop, | |
95 | struct property *oldprop) | |
96 | { | |
97 | struct proc_dir_entry *ent; | |
98 | ||
99 | for (ent = pde->subdir; ent != NULL; ent = ent->next) | |
100 | if (ent->data == oldprop) | |
101 | break; | |
102 | if (ent == NULL) { | |
103 | printk(KERN_WARNING "device-tree: property \"%s\" " | |
104 | " does not exist\n", oldprop->name); | |
105 | } else { | |
106 | ent->data = newprop; | |
107 | ent->size = newprop->length; | |
108 | } | |
109 | } | |
110 | ||
5149fa47 ME |
111 | /* |
112 | * Various dodgy firmware might give us nodes and/or properties with | |
113 | * conflicting names. That's generally ok, except for exporting via /proc, | |
114 | * so munge names here to ensure they're unique. | |
115 | */ | |
116 | ||
117 | static int duplicate_name(struct proc_dir_entry *de, const char *name) | |
118 | { | |
119 | struct proc_dir_entry *ent; | |
120 | int found = 0; | |
121 | ||
122 | spin_lock(&proc_subdir_lock); | |
123 | ||
124 | for (ent = de->subdir; ent != NULL; ent = ent->next) { | |
125 | if (strcmp(ent->name, name) == 0) { | |
126 | found = 1; | |
127 | break; | |
128 | } | |
129 | } | |
130 | ||
131 | spin_unlock(&proc_subdir_lock); | |
132 | ||
133 | return found; | |
134 | } | |
135 | ||
136 | static const char *fixup_name(struct device_node *np, struct proc_dir_entry *de, | |
137 | const char *name) | |
138 | { | |
139 | char *fixed_name; | |
140 | int fixup_len = strlen(name) + 2 + 1; /* name + #x + \0 */ | |
141 | int i = 1, size; | |
142 | ||
143 | realloc: | |
144 | fixed_name = kmalloc(fixup_len, GFP_KERNEL); | |
145 | if (fixed_name == NULL) { | |
146 | printk(KERN_ERR "device-tree: Out of memory trying to fixup " | |
147 | "name \"%s\"\n", name); | |
148 | return name; | |
149 | } | |
150 | ||
151 | retry: | |
152 | size = snprintf(fixed_name, fixup_len, "%s#%d", name, i); | |
153 | size++; /* account for NULL */ | |
154 | ||
155 | if (size > fixup_len) { | |
156 | /* We ran out of space, free and reallocate. */ | |
157 | kfree(fixed_name); | |
158 | fixup_len = size; | |
159 | goto realloc; | |
160 | } | |
161 | ||
162 | if (duplicate_name(de, fixed_name)) { | |
163 | /* Multiple duplicates. Retry with a different offset. */ | |
164 | i++; | |
165 | goto retry; | |
166 | } | |
167 | ||
168 | printk(KERN_WARNING "device-tree: Duplicate name in %s, " | |
169 | "renamed to \"%s\"\n", np->full_name, fixed_name); | |
170 | ||
171 | return fixed_name; | |
172 | } | |
173 | ||
1da177e4 LT |
174 | /* |
175 | * Process a node, adding entries for its children and its properties. | |
176 | */ | |
5f64f739 BH |
177 | void proc_device_tree_add_node(struct device_node *np, |
178 | struct proc_dir_entry *de) | |
1da177e4 LT |
179 | { |
180 | struct property *pp; | |
181 | struct proc_dir_entry *ent; | |
5f64f739 | 182 | struct device_node *child; |
5f64f739 | 183 | const char *p; |
1da177e4 LT |
184 | |
185 | set_node_proc_entry(np, de); | |
5f64f739 | 186 | for (child = NULL; (child = of_get_next_child(np, child));) { |
5149fa47 | 187 | /* Use everything after the last slash, or the full name */ |
1da177e4 LT |
188 | p = strrchr(child->full_name, '/'); |
189 | if (!p) | |
190 | p = child->full_name; | |
191 | else | |
192 | ++p; | |
5149fa47 ME |
193 | |
194 | if (duplicate_name(de, p)) | |
195 | p = fixup_name(np, de, p); | |
196 | ||
1da177e4 | 197 | ent = proc_mkdir(p, de); |
bcac2b1b | 198 | if (ent == NULL) |
1da177e4 | 199 | break; |
1da177e4 | 200 | proc_device_tree_add_node(child, ent); |
5f64f739 BH |
201 | } |
202 | of_node_put(child); | |
5149fa47 | 203 | |
bcac2b1b | 204 | for (pp = np->properties; pp != NULL; pp = pp->next) { |
5149fa47 ME |
205 | p = pp->name; |
206 | ||
207 | if (duplicate_name(de, p)) | |
208 | p = fixup_name(np, de, p); | |
5f64f739 | 209 | |
5149fa47 | 210 | ent = __proc_device_tree_add_prop(de, pp, p); |
bcac2b1b | 211 | if (ent == NULL) |
1da177e4 | 212 | break; |
1da177e4 | 213 | } |
1da177e4 LT |
214 | } |
215 | ||
216 | /* | |
217 | * Called on initialization to set up the /proc/device-tree subtree | |
218 | */ | |
1e0edd3f | 219 | void __init proc_device_tree_init(void) |
1da177e4 LT |
220 | { |
221 | struct device_node *root; | |
6b82b3e4 | 222 | |
1da177e4 | 223 | proc_device_tree = proc_mkdir("device-tree", NULL); |
bcac2b1b | 224 | if (proc_device_tree == NULL) |
1da177e4 LT |
225 | return; |
226 | root = of_find_node_by_path("/"); | |
bcac2b1b | 227 | if (root == NULL) { |
1da177e4 LT |
228 | printk(KERN_ERR "/proc/device-tree: can't find root\n"); |
229 | return; | |
230 | } | |
231 | proc_device_tree_add_node(root, proc_device_tree); | |
232 | of_node_put(root); | |
233 | } |