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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>
Al Viro3174c212009-04-07 13:19:18 -040014#include "internal.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070015
16#ifndef HAVE_ARCH_DEVTREE_FIXUPS
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +100017static inline void set_node_proc_entry(struct device_node *np,
18 struct proc_dir_entry *de)
Linus Torvalds1da177e2005-04-16 15:20:36 -070019{
20}
21#endif
22
23static struct proc_dir_entry *proc_device_tree;
24
25/*
26 * Supply data on a read from /proc/device-tree/node/property.
27 */
28static 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;
Stephen Rothwell1a381472007-04-03 10:58:52 +100043 memcpy(page, (char *)pp->value + off, n);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 *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
53/*
Benjamin Herrenschmidt183d0202005-11-07 14:29:02 +110054 * Add a property to a node
55 */
56static struct proc_dir_entry *
Michael Ellerman5149fa42006-03-27 14:26:26 +110057__proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp,
58 const char *name)
Benjamin Herrenschmidt183d0202005-11-07 14:29:02 +110059{
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 */
Michael Ellerman5149fa42006-03-27 14:26:26 +110066 ent = create_proc_read_entry(name,
67 strncmp(name, "security-", 9)
Benjamin Herrenschmidt183d0202005-11-07 14:29:02 +110068 ? S_IRUGO : S_IRUSR, de,
69 property_read_proc, pp);
70 if (ent == NULL)
71 return NULL;
72
Michael Ellerman5149fa42006-03-27 14:26:26 +110073 if (!strncmp(name, "security-", 9))
Benjamin Herrenschmidt183d0202005-11-07 14:29:02 +110074 ent->size = 0; /* don't leak number of password chars */
75 else
76 ent->size = pp->length;
77
78 return ent;
79}
80
81
82void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop)
83{
Michael Ellerman5149fa42006-03-27 14:26:26 +110084 __proc_device_tree_add_prop(pde, prop, prop->name);
Benjamin Herrenschmidt183d0202005-11-07 14:29:02 +110085}
86
Dave C Boutcher898b5392006-01-12 16:07:17 -060087void proc_device_tree_remove_prop(struct proc_dir_entry *pde,
88 struct property *prop)
89{
90 remove_proc_entry(prop->name, pde);
91}
92
93void 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
Benjamin Herrenschmidt183d0202005-11-07 14:29:02 +1100111/*
Michael Ellerman5149fa42006-03-27 14:26:26 +1100112 * 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
117static 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
136static 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
143realloc:
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
151retry:
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
174/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 * Process a node, adding entries for its children and its properties.
176 */
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000177void proc_device_tree_add_node(struct device_node *np,
178 struct proc_dir_entry *de)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179{
180 struct property *pp;
181 struct proc_dir_entry *ent;
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000182 struct device_node *child;
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000183 const char *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184
185 set_node_proc_entry(np, de);
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000186 for (child = NULL; (child = of_get_next_child(np, child));) {
Michael Ellerman5149fa42006-03-27 14:26:26 +1100187 /* Use everything after the last slash, or the full name */
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000188 p = strrchr(child->full_name, '/');
189 if (!p)
190 p = child->full_name;
191 else
192 ++p;
Michael Ellerman5149fa42006-03-27 14:26:26 +1100193
194 if (duplicate_name(de, p))
195 p = fixup_name(np, de, p);
196
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000197 ent = proc_mkdir(p, de);
Michal Simekbcac2b12009-06-17 16:25:59 -0700198 if (ent == NULL)
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000199 break;
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000200 proc_device_tree_add_node(child, ent);
201 }
202 of_node_put(child);
Benjamin Herrenschmidt5f64f732005-06-01 17:07:27 +1000203
Michal Simekbcac2b12009-06-17 16:25:59 -0700204 for (pp = np->properties; pp != NULL; pp = pp->next) {
Michael Ellerman5149fa42006-03-27 14:26:26 +1100205 p = pp->name;
206
207 if (duplicate_name(de, p))
208 p = fixup_name(np, de, p);
209
210 ent = __proc_device_tree_add_prop(de, pp, p);
Michal Simekbcac2b12009-06-17 16:25:59 -0700211 if (ent == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214}
215
216/*
217 * Called on initialization to set up the /proc/device-tree subtree
218 */
Alexey Dobriyan1e0edd32008-10-17 05:07:44 +0400219void __init proc_device_tree_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220{
221 struct device_node *root;
Anton Vorontsov6b82b3e2008-12-09 09:47:29 +0000222
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 proc_device_tree = proc_mkdir("device-tree", NULL);
Michal Simekbcac2b12009-06-17 16:25:59 -0700224 if (proc_device_tree == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 return;
226 root = of_find_node_by_path("/");
Michal Simekbcac2b12009-06-17 16:25:59 -0700227 if (root == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 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}