Commit | Line | Data |
---|---|---|
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> | |
e22f6283 | 10 | #include <linux/seq_file.h> |
87ebdc00 | 11 | #include <linux/printk.h> |
1da177e4 LT |
12 | #include <linux/stat.h> |
13 | #include <linux/string.h> | |
50ab2fe1 | 14 | #include <linux/of.h> |
75fc0cf6 | 15 | #include <linux/export.h> |
5a0e3ad6 | 16 | #include <linux/slab.h> |
1da177e4 | 17 | #include <asm/uaccess.h> |
3174c21b | 18 | #include "internal.h" |
1da177e4 | 19 | |
5f64f739 BH |
20 | static inline void set_node_proc_entry(struct device_node *np, |
21 | struct proc_dir_entry *de) | |
1da177e4 | 22 | { |
8cfb3343 | 23 | np->pde = de; |
8cfb3343 | 24 | } |
1da177e4 LT |
25 | |
26 | static struct proc_dir_entry *proc_device_tree; | |
27 | ||
28 | /* | |
29 | * Supply data on a read from /proc/device-tree/node/property. | |
30 | */ | |
e22f6283 | 31 | static int property_proc_show(struct seq_file *m, void *v) |
1da177e4 | 32 | { |
e22f6283 | 33 | struct property *pp = m->private; |
1da177e4 | 34 | |
e22f6283 AD |
35 | seq_write(m, pp->value, pp->length); |
36 | return 0; | |
1da177e4 LT |
37 | } |
38 | ||
e22f6283 AD |
39 | static int property_proc_open(struct inode *inode, struct file *file) |
40 | { | |
c30480b9 | 41 | return single_open(file, property_proc_show, __PDE_DATA(inode)); |
e22f6283 AD |
42 | } |
43 | ||
44 | static const struct file_operations property_proc_fops = { | |
45 | .owner = THIS_MODULE, | |
46 | .open = property_proc_open, | |
47 | .read = seq_read, | |
48 | .llseek = seq_lseek, | |
49 | .release = single_release, | |
50 | }; | |
51 | ||
1da177e4 LT |
52 | /* |
53 | * For a node with a name like "gc@10", we make symlinks called "gc" | |
54 | * and "@10" to it. | |
55 | */ | |
56 | ||
183d0202 BH |
57 | /* |
58 | * Add a property to a node | |
59 | */ | |
60 | static struct proc_dir_entry * | |
5149fa47 ME |
61 | __proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp, |
62 | const char *name) | |
183d0202 BH |
63 | { |
64 | struct proc_dir_entry *ent; | |
65 | ||
66 | /* | |
67 | * Unfortunately proc_register puts each new entry | |
68 | * at the beginning of the list. So we rearrange them. | |
69 | */ | |
e22f6283 AD |
70 | ent = proc_create_data(name, |
71 | strncmp(name, "security-", 9) ? S_IRUGO : S_IRUSR, | |
72 | de, &property_proc_fops, pp); | |
183d0202 BH |
73 | if (ent == NULL) |
74 | return NULL; | |
75 | ||
5149fa47 | 76 | if (!strncmp(name, "security-", 9)) |
cdf7e8dd | 77 | proc_set_size(ent, 0); /* don't leak number of password chars */ |
183d0202 | 78 | else |
cdf7e8dd | 79 | proc_set_size(ent, pp->length); |
183d0202 BH |
80 | |
81 | return ent; | |
82 | } | |
83 | ||
84 | ||
85 | void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop) | |
86 | { | |
5149fa47 | 87 | __proc_device_tree_add_prop(pde, prop, prop->name); |
183d0202 BH |
88 | } |
89 | ||
898b5395 DB |
90 | void proc_device_tree_remove_prop(struct proc_dir_entry *pde, |
91 | struct property *prop) | |
92 | { | |
93 | remove_proc_entry(prop->name, pde); | |
94 | } | |
95 | ||
96 | void proc_device_tree_update_prop(struct proc_dir_entry *pde, | |
97 | struct property *newprop, | |
98 | struct property *oldprop) | |
99 | { | |
100 | struct proc_dir_entry *ent; | |
101 | ||
475d0094 DA |
102 | if (!oldprop) { |
103 | proc_device_tree_add_prop(pde, newprop); | |
104 | return; | |
105 | } | |
106 | ||
898b5395 DB |
107 | for (ent = pde->subdir; ent != NULL; ent = ent->next) |
108 | if (ent->data == oldprop) | |
109 | break; | |
110 | if (ent == NULL) { | |
87ebdc00 AM |
111 | pr_warn("device-tree: property \"%s\" does not exist\n", |
112 | oldprop->name); | |
898b5395 DB |
113 | } else { |
114 | ent->data = newprop; | |
115 | ent->size = newprop->length; | |
116 | } | |
117 | } | |
118 | ||
5149fa47 ME |
119 | /* |
120 | * Various dodgy firmware might give us nodes and/or properties with | |
121 | * conflicting names. That's generally ok, except for exporting via /proc, | |
122 | * so munge names here to ensure they're unique. | |
123 | */ | |
124 | ||
125 | static int duplicate_name(struct proc_dir_entry *de, const char *name) | |
126 | { | |
127 | struct proc_dir_entry *ent; | |
128 | int found = 0; | |
129 | ||
130 | spin_lock(&proc_subdir_lock); | |
131 | ||
132 | for (ent = de->subdir; ent != NULL; ent = ent->next) { | |
133 | if (strcmp(ent->name, name) == 0) { | |
134 | found = 1; | |
135 | break; | |
136 | } | |
137 | } | |
138 | ||
139 | spin_unlock(&proc_subdir_lock); | |
140 | ||
141 | return found; | |
142 | } | |
143 | ||
144 | static const char *fixup_name(struct device_node *np, struct proc_dir_entry *de, | |
145 | const char *name) | |
146 | { | |
147 | char *fixed_name; | |
148 | int fixup_len = strlen(name) + 2 + 1; /* name + #x + \0 */ | |
149 | int i = 1, size; | |
150 | ||
151 | realloc: | |
152 | fixed_name = kmalloc(fixup_len, GFP_KERNEL); | |
153 | if (fixed_name == NULL) { | |
87ebdc00 AM |
154 | pr_err("device-tree: Out of memory trying to fixup " |
155 | "name \"%s\"\n", name); | |
5149fa47 ME |
156 | return name; |
157 | } | |
158 | ||
159 | retry: | |
160 | size = snprintf(fixed_name, fixup_len, "%s#%d", name, i); | |
161 | size++; /* account for NULL */ | |
162 | ||
163 | if (size > fixup_len) { | |
164 | /* We ran out of space, free and reallocate. */ | |
165 | kfree(fixed_name); | |
166 | fixup_len = size; | |
167 | goto realloc; | |
168 | } | |
169 | ||
170 | if (duplicate_name(de, fixed_name)) { | |
171 | /* Multiple duplicates. Retry with a different offset. */ | |
172 | i++; | |
173 | goto retry; | |
174 | } | |
175 | ||
87ebdc00 AM |
176 | pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n", |
177 | np->full_name, fixed_name); | |
5149fa47 ME |
178 | |
179 | return fixed_name; | |
180 | } | |
181 | ||
1da177e4 LT |
182 | /* |
183 | * Process a node, adding entries for its children and its properties. | |
184 | */ | |
5f64f739 BH |
185 | void proc_device_tree_add_node(struct device_node *np, |
186 | struct proc_dir_entry *de) | |
1da177e4 LT |
187 | { |
188 | struct property *pp; | |
189 | struct proc_dir_entry *ent; | |
5f64f739 | 190 | struct device_node *child; |
5f64f739 | 191 | const char *p; |
1da177e4 LT |
192 | |
193 | set_node_proc_entry(np, de); | |
5f64f739 | 194 | for (child = NULL; (child = of_get_next_child(np, child));) { |
5149fa47 | 195 | /* Use everything after the last slash, or the full name */ |
f9a00e87 | 196 | p = kbasename(child->full_name); |
5149fa47 ME |
197 | |
198 | if (duplicate_name(de, p)) | |
199 | p = fixup_name(np, de, p); | |
200 | ||
1da177e4 | 201 | ent = proc_mkdir(p, de); |
bcac2b1b | 202 | if (ent == NULL) |
1da177e4 | 203 | break; |
1da177e4 | 204 | proc_device_tree_add_node(child, ent); |
5f64f739 BH |
205 | } |
206 | of_node_put(child); | |
5149fa47 | 207 | |
bcac2b1b | 208 | for (pp = np->properties; pp != NULL; pp = pp->next) { |
5149fa47 ME |
209 | p = pp->name; |
210 | ||
9f069af5 ME |
211 | if (strchr(p, '/')) |
212 | continue; | |
213 | ||
5149fa47 ME |
214 | if (duplicate_name(de, p)) |
215 | p = fixup_name(np, de, p); | |
5f64f739 | 216 | |
5149fa47 | 217 | ent = __proc_device_tree_add_prop(de, pp, p); |
bcac2b1b | 218 | if (ent == NULL) |
1da177e4 | 219 | break; |
1da177e4 | 220 | } |
1da177e4 LT |
221 | } |
222 | ||
223 | /* | |
224 | * Called on initialization to set up the /proc/device-tree subtree | |
225 | */ | |
1e0edd3f | 226 | void __init proc_device_tree_init(void) |
1da177e4 LT |
227 | { |
228 | struct device_node *root; | |
6b82b3e4 | 229 | |
1da177e4 | 230 | proc_device_tree = proc_mkdir("device-tree", NULL); |
bcac2b1b | 231 | if (proc_device_tree == NULL) |
1da177e4 LT |
232 | return; |
233 | root = of_find_node_by_path("/"); | |
bcac2b1b | 234 | if (root == NULL) { |
c1d867a5 | 235 | remove_proc_entry("device-tree", NULL); |
8aaccf7f | 236 | pr_debug("/proc/device-tree: can't find root\n"); |
1da177e4 LT |
237 | return; |
238 | } | |
239 | proc_device_tree_add_node(root, proc_device_tree); | |
240 | of_node_put(root); | |
241 | } |