2 * proc_devtree.c - handles /proc/device-tree
4 * Copyright 1997 Paul Mackerras
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>
12 #include <asm/uaccess.h>
14 #ifndef HAVE_ARCH_DEVTREE_FIXUPS
15 static inline void set_node_proc_entry(struct device_node *np, struct proc_dir_entry *de)
19 static void inline set_node_name_link(struct device_node *np, struct proc_dir_entry *de)
23 static void inline set_node_addr_link(struct device_node *np, struct proc_dir_entry *de)
28 static struct proc_dir_entry *proc_device_tree;
31 * Supply data on a read from /proc/device-tree/node/property.
33 static int property_read_proc(char *page, char **start, off_t off,
34 int count, int *eof, void *data)
36 struct property *pp = data;
39 if (off >= pp->length) {
48 memcpy(page, pp->value + off, n);
54 * For a node with a name like "gc@10", we make symlinks called "gc"
59 * Process a node, adding entries for its children and its properties.
61 void proc_device_tree_add_node(struct device_node *np, struct proc_dir_entry *de)
64 struct proc_dir_entry *ent;
65 struct device_node *child, *sib;
68 struct proc_dir_entry *list, **lastp, *al;
70 set_node_proc_entry(np, de);
72 for (pp = np->properties; pp != 0; pp = pp->next) {
74 * Unfortunately proc_register puts each new entry
75 * at the beginning of the list. So we rearrange them.
77 ent = create_proc_read_entry(pp->name, strncmp(pp->name, "security-", 9) ?
78 S_IRUGO : S_IRUSR, de, property_read_proc, pp);
81 if (!strncmp(pp->name, "security-", 9))
82 ent->size = 0; /* don't leak number of password chars */
84 ent->size = pp->length;
89 while ((child = of_get_next_child(np, child))) {
90 p = strrchr(child->full_name, '/');
95 /* chop off '@0' if the name ends with that */
97 if (l > 2 && p[l-2] == '@' && p[l-1] == '0')
99 ent = proc_mkdir(p, de);
104 proc_device_tree_add_node(child, ent);
107 * If we left the address part on the name, consider
108 * adding symlinks from the name and address parts.
110 if (p[l] != 0 || (at = strchr(p, '@')) == 0)
114 * If this is the first node with a given name property,
115 * add a symlink with the name property as its name.
118 while ((sib = of_get_next_child(np, sib)) && sib != child)
119 if (sib->name && strcmp(sib->name, child->name) == 0)
121 if (sib == child && strncmp(p, child->name, l) != 0) {
122 al = proc_symlink(child->name, de, ent->name);
127 set_node_name_link(child, al);
133 * Add another directory with the @address part as its name.
135 al = proc_symlink(at, de, ent->name);
138 set_node_addr_link(child, al);
148 * Called on initialization to set up the /proc/device-tree subtree
150 void proc_device_tree_init(void)
152 struct device_node *root;
155 proc_device_tree = proc_mkdir("device-tree", 0);
156 if (proc_device_tree == 0)
158 root = of_find_node_by_path("/");
160 printk(KERN_ERR "/proc/device-tree: can't find root\n");
163 proc_device_tree_add_node(root, proc_device_tree);