blob: de2bba5a3440ad2b4ba04d4f6fabbfe36a7f46f6 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * proc_devtree.c - handles /proc/device-tree
3 *
4 * Copyright 1997 Paul Mackerras
5 */
6#include <linux/errno.h>
Alexey Dobriyan1e0edd32008-10-17 05:07:44 +04007#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008#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>
14
15#ifndef HAVE_ARCH_DEVTREE_FIXUPS
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +100016static inline void set_node_proc_entry(struct device_node *np,
17 struct proc_dir_entry *de)
Linus Torvalds1da177e2005-04-16 15:20:36 -070018{
19}
20#endif
21
22static struct proc_dir_entry *proc_device_tree;
23
24/*
25 * Supply data on a read from /proc/device-tree/node/property.
26 */
27static int property_read_proc(char *page, char **start, off_t off,
28 int count, int *eof, void *data)
29{
30 struct property *pp = data;
31 int n;
32
33 if (off >= pp->length) {
34 *eof = 1;
35 return 0;
36 }
37 n = pp->length - off;
38 if (n > count)
39 n = count;
40 else
41 *eof = 1;
Stephen Rothwell1a381472007-04-03 10:58:52 +100042 memcpy(page, (char *)pp->value + off, n);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 *start = page;
44 return n;
45}
46
47/*
48 * For a node with a name like "gc@10", we make symlinks called "gc"
49 * and "@10" to it.
50 */
51
52/*
Benjamin Herrenschmidt183d0202005-11-07 14:29:02 +110053 * Add a property to a node
54 */
55static struct proc_dir_entry *
Michael Ellerman5149fa42006-03-27 14:26:26 +110056__proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp,
57 const char *name)
Benjamin Herrenschmidt183d0202005-11-07 14:29:02 +110058{
59 struct proc_dir_entry *ent;
60
61 /*
62 * Unfortunately proc_register puts each new entry
63 * at the beginning of the list. So we rearrange them.
64 */
Michael Ellerman5149fa42006-03-27 14:26:26 +110065 ent = create_proc_read_entry(name,
66 strncmp(name, "security-", 9)
Benjamin Herrenschmidt183d0202005-11-07 14:29:02 +110067 ? S_IRUGO : S_IRUSR, de,
68 property_read_proc, pp);
69 if (ent == NULL)
70 return NULL;
71
Michael Ellerman5149fa42006-03-27 14:26:26 +110072 if (!strncmp(name, "security-", 9))
Benjamin Herrenschmidt183d0202005-11-07 14:29:02 +110073 ent->size = 0; /* don't leak number of password chars */
74 else
75 ent->size = pp->length;
76
77 return ent;
78}
79
80
81void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop)
82{
Michael Ellerman5149fa42006-03-27 14:26:26 +110083 __proc_device_tree_add_prop(pde, prop, prop->name);
Benjamin Herrenschmidt183d0202005-11-07 14:29:02 +110084}
85
Dave C Boutcher898b5392006-01-12 16:07:17 -060086void proc_device_tree_remove_prop(struct proc_dir_entry *pde,
87 struct property *prop)
88{
89 remove_proc_entry(prop->name, pde);
90}
91
92void proc_device_tree_update_prop(struct proc_dir_entry *pde,
93 struct property *newprop,
94 struct property *oldprop)
95{
96 struct proc_dir_entry *ent;
97
98 for (ent = pde->subdir; ent != NULL; ent = ent->next)
99 if (ent->data == oldprop)
100 break;
101 if (ent == NULL) {
102 printk(KERN_WARNING "device-tree: property \"%s\" "
103 " does not exist\n", oldprop->name);
104 } else {
105 ent->data = newprop;
106 ent->size = newprop->length;
107 }
108}
109
Benjamin Herrenschmidt183d0202005-11-07 14:29:02 +1100110/*
Michael Ellerman5149fa42006-03-27 14:26:26 +1100111 * Various dodgy firmware might give us nodes and/or properties with
112 * conflicting names. That's generally ok, except for exporting via /proc,
113 * so munge names here to ensure they're unique.
114 */
115
116static int duplicate_name(struct proc_dir_entry *de, const char *name)
117{
118 struct proc_dir_entry *ent;
119 int found = 0;
120
121 spin_lock(&proc_subdir_lock);
122
123 for (ent = de->subdir; ent != NULL; ent = ent->next) {
124 if (strcmp(ent->name, name) == 0) {
125 found = 1;
126 break;
127 }
128 }
129
130 spin_unlock(&proc_subdir_lock);
131
132 return found;
133}
134
135static const char *fixup_name(struct device_node *np, struct proc_dir_entry *de,
136 const char *name)
137{
138 char *fixed_name;
139 int fixup_len = strlen(name) + 2 + 1; /* name + #x + \0 */
140 int i = 1, size;
141
142realloc:
143 fixed_name = kmalloc(fixup_len, GFP_KERNEL);
144 if (fixed_name == NULL) {
145 printk(KERN_ERR "device-tree: Out of memory trying to fixup "
146 "name \"%s\"\n", name);
147 return name;
148 }
149
150retry:
151 size = snprintf(fixed_name, fixup_len, "%s#%d", name, i);
152 size++; /* account for NULL */
153
154 if (size > fixup_len) {
155 /* We ran out of space, free and reallocate. */
156 kfree(fixed_name);
157 fixup_len = size;
158 goto realloc;
159 }
160
161 if (duplicate_name(de, fixed_name)) {
162 /* Multiple duplicates. Retry with a different offset. */
163 i++;
164 goto retry;
165 }
166
167 printk(KERN_WARNING "device-tree: Duplicate name in %s, "
168 "renamed to \"%s\"\n", np->full_name, fixed_name);
169
170 return fixed_name;
171}
172
173/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 * Process a node, adding entries for its children and its properties.
175 */
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000176void proc_device_tree_add_node(struct device_node *np,
177 struct proc_dir_entry *de)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178{
179 struct property *pp;
180 struct proc_dir_entry *ent;
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000181 struct device_node *child;
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000182 const char *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
184 set_node_proc_entry(np, de);
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000185 for (child = NULL; (child = of_get_next_child(np, child));) {
Michael Ellerman5149fa42006-03-27 14:26:26 +1100186 /* Use everything after the last slash, or the full name */
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000187 p = strrchr(child->full_name, '/');
188 if (!p)
189 p = child->full_name;
190 else
191 ++p;
Michael Ellerman5149fa42006-03-27 14:26:26 +1100192
193 if (duplicate_name(de, p))
194 p = fixup_name(np, de, p);
195
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000196 ent = proc_mkdir(p, de);
197 if (ent == 0)
198 break;
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000199 proc_device_tree_add_node(child, ent);
200 }
201 of_node_put(child);
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000202
Michael Ellerman5149fa42006-03-27 14:26:26 +1100203 for (pp = np->properties; pp != 0; pp = pp->next) {
204 p = pp->name;
205
206 if (duplicate_name(de, p))
207 p = fixup_name(np, de, p);
208
209 ent = __proc_device_tree_add_prop(de, pp, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 if (ent == 0)
211 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213}
214
215/*
216 * Called on initialization to set up the /proc/device-tree subtree
217 */
Alexey Dobriyan1e0edd32008-10-17 05:07:44 +0400218void __init proc_device_tree_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219{
220 struct device_node *root;
Anton Vorontsov6b82b3e2008-12-09 09:47:29 +0000221
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 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}