Linux kernel mirror (for testing)
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linux
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
15static inline void set_node_proc_entry(struct device_node *np, struct proc_dir_entry *de)
16{
17}
18
19static void inline set_node_name_link(struct device_node *np, struct proc_dir_entry *de)
20{
21}
22
23static void inline set_node_addr_link(struct device_node *np, struct proc_dir_entry *de)
24{
25}
26#endif
27
28static struct proc_dir_entry *proc_device_tree;
29
30/*
31 * Supply data on a read from /proc/device-tree/node/property.
32 */
33static int property_read_proc(char *page, char **start, off_t off,
34 int count, int *eof, void *data)
35{
36 struct property *pp = data;
37 int n;
38
39 if (off >= pp->length) {
40 *eof = 1;
41 return 0;
42 }
43 n = pp->length - off;
44 if (n > count)
45 n = count;
46 else
47 *eof = 1;
48 memcpy(page, pp->value + off, n);
49 *start = page;
50 return n;
51}
52
53/*
54 * For a node with a name like "gc@10", we make symlinks called "gc"
55 * and "@10" to it.
56 */
57
58/*
59 * Process a node, adding entries for its children and its properties.
60 */
61void proc_device_tree_add_node(struct device_node *np, struct proc_dir_entry *de)
62{
63 struct property *pp;
64 struct proc_dir_entry *ent;
65 struct device_node *child, *sib;
66 const char *p, *at;
67 int l;
68 struct proc_dir_entry *list, **lastp, *al;
69
70 set_node_proc_entry(np, de);
71 lastp = &list;
72 for (pp = np->properties; pp != 0; pp = pp->next) {
73 /*
74 * Unfortunately proc_register puts each new entry
75 * at the beginning of the list. So we rearrange them.
76 */
77 ent = create_proc_read_entry(pp->name, strncmp(pp->name, "security-", 9) ?
78 S_IRUGO : S_IRUSR, de, property_read_proc, pp);
79 if (ent == 0)
80 break;
81 if (!strncmp(pp->name, "security-", 9))
82 ent->size = 0; /* don't leak number of password chars */
83 else
84 ent->size = pp->length;
85 *lastp = ent;
86 lastp = &ent->next;
87 }
88 child = NULL;
89 while ((child = of_get_next_child(np, child))) {
90 p = strrchr(child->full_name, '/');
91 if (!p)
92 p = child->full_name;
93 else
94 ++p;
95 /* chop off '@0' if the name ends with that */
96 l = strlen(p);
97 if (l > 2 && p[l-2] == '@' && p[l-1] == '0')
98 l -= 2;
99 ent = proc_mkdir(p, de);
100 if (ent == 0)
101 break;
102 *lastp = ent;
103 lastp = &ent->next;
104 proc_device_tree_add_node(child, ent);
105
106 /*
107 * If we left the address part on the name, consider
108 * adding symlinks from the name and address parts.
109 */
110 if (p[l] != 0 || (at = strchr(p, '@')) == 0)
111 continue;
112
113 /*
114 * If this is the first node with a given name property,
115 * add a symlink with the name property as its name.
116 */
117 sib = NULL;
118 while ((sib = of_get_next_child(np, sib)) && sib != child)
119 if (sib->name && strcmp(sib->name, child->name) == 0)
120 break;
121 if (sib == child && strncmp(p, child->name, l) != 0) {
122 al = proc_symlink(child->name, de, ent->name);
123 if (al == 0) {
124 of_node_put(sib);
125 break;
126 }
127 set_node_name_link(child, al);
128 *lastp = al;
129 lastp = &al->next;
130 }
131 of_node_put(sib);
132 /*
133 * Add another directory with the @address part as its name.
134 */
135 al = proc_symlink(at, de, ent->name);
136 if (al == 0)
137 break;
138 set_node_addr_link(child, al);
139 *lastp = al;
140 lastp = &al->next;
141 }
142 of_node_put(child);
143 *lastp = NULL;
144 de->subdir = list;
145}
146
147/*
148 * Called on initialization to set up the /proc/device-tree subtree
149 */
150void proc_device_tree_init(void)
151{
152 struct device_node *root;
153 if ( !have_of )
154 return;
155 proc_device_tree = proc_mkdir("device-tree", NULL);
156 if (proc_device_tree == 0)
157 return;
158 root = of_find_node_by_path("/");
159 if (root == 0) {
160 printk(KERN_ERR "/proc/device-tree: can't find root\n");
161 return;
162 }
163 proc_device_tree_add_node(root, proc_device_tree);
164 of_node_put(root);
165}