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-rw-r--r--fs/proc/proc_devtree.c165
1 files changed, 165 insertions, 0 deletions
diff --git a/fs/proc/proc_devtree.c b/fs/proc/proc_devtree.c
new file mode 100644
index 000000000000..67423c696c0a
--- /dev/null
+++ b/fs/proc/proc_devtree.c
@@ -0,0 +1,165 @@
+/*
+ * proc_devtree.c - handles /proc/device-tree
+ *
+ * Copyright 1997 Paul Mackerras
+ */
+#include <linux/errno.h>
+#include <linux/time.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <asm/prom.h>
+#include <asm/uaccess.h>
+
+#ifndef HAVE_ARCH_DEVTREE_FIXUPS
+static inline void set_node_proc_entry(struct device_node *np, struct proc_dir_entry *de)
+{
+}
+
+static void inline set_node_name_link(struct device_node *np, struct proc_dir_entry *de)
+{
+}
+
+static void inline set_node_addr_link(struct device_node *np, struct proc_dir_entry *de)
+{
+}
+#endif
+
+static struct proc_dir_entry *proc_device_tree;
+
+/*
+ * Supply data on a read from /proc/device-tree/node/property.
+ */
+static int property_read_proc(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ struct property *pp = data;
+ int n;
+
+ if (off >= pp->length) {
+ *eof = 1;
+ return 0;
+ }
+ n = pp->length - off;
+ if (n > count)
+ n = count;
+ else
+ *eof = 1;
+ memcpy(page, pp->value + off, n);
+ *start = page;
+ return n;
+}
+
+/*
+ * For a node with a name like "gc@10", we make symlinks called "gc"
+ * and "@10" to it.
+ */
+
+/*
+ * Process a node, adding entries for its children and its properties.
+ */
+void proc_device_tree_add_node(struct device_node *np, struct proc_dir_entry *de)
+{
+ struct property *pp;
+ struct proc_dir_entry *ent;
+ struct device_node *child, *sib;
+ const char *p, *at;
+ int l;
+ struct proc_dir_entry *list, **lastp, *al;
+
+ set_node_proc_entry(np, de);
+ lastp = &list;
+ for (pp = np->properties; pp != 0; pp = pp->next) {
+ /*
+ * Unfortunately proc_register puts each new entry
+ * at the beginning of the list. So we rearrange them.
+ */
+ ent = create_proc_read_entry(pp->name, strncmp(pp->name, "security-", 9) ?
+ S_IRUGO : S_IRUSR, de, property_read_proc, pp);
+ if (ent == 0)
+ break;
+ if (!strncmp(pp->name, "security-", 9))
+ ent->size = 0; /* don't leak number of password chars */
+ else
+ ent->size = pp->length;
+ *lastp = ent;
+ lastp = &ent->next;
+ }
+ child = NULL;
+ while ((child = of_get_next_child(np, child))) {
+ p = strrchr(child->full_name, '/');
+ if (!p)
+ p = child->full_name;
+ else
+ ++p;
+ /* chop off '@0' if the name ends with that */
+ l = strlen(p);
+ if (l > 2 && p[l-2] == '@' && p[l-1] == '0')
+ l -= 2;
+ ent = proc_mkdir(p, de);
+ if (ent == 0)
+ break;
+ *lastp = ent;
+ lastp = &ent->next;
+ proc_device_tree_add_node(child, ent);
+
+ /*
+ * If we left the address part on the name, consider
+ * adding symlinks from the name and address parts.
+ */
+ if (p[l] != 0 || (at = strchr(p, '@')) == 0)
+ continue;
+
+ /*
+ * If this is the first node with a given name property,
+ * add a symlink with the name property as its name.
+ */
+ sib = NULL;
+ while ((sib = of_get_next_child(np, sib)) && sib != child)
+ if (sib->name && strcmp(sib->name, child->name) == 0)
+ break;
+ if (sib == child && strncmp(p, child->name, l) != 0) {
+ al = proc_symlink(child->name, de, ent->name);
+ if (al == 0) {
+ of_node_put(sib);
+ break;
+ }
+ set_node_name_link(child, al);
+ *lastp = al;
+ lastp = &al->next;
+ }
+ of_node_put(sib);
+ /*
+ * Add another directory with the @address part as its name.
+ */
+ al = proc_symlink(at, de, ent->name);
+ if (al == 0)
+ break;
+ set_node_addr_link(child, al);
+ *lastp = al;
+ lastp = &al->next;
+ }
+ of_node_put(child);
+ *lastp = NULL;
+ de->subdir = list;
+}
+
+/*
+ * Called on initialization to set up the /proc/device-tree subtree
+ */
+void proc_device_tree_init(void)
+{
+ struct device_node *root;
+ if ( !have_of )
+ return;
+ proc_device_tree = proc_mkdir("device-tree", NULL);
+ if (proc_device_tree == 0)
+ return;
+ root = of_find_node_by_path("/");
+ if (root == 0) {
+ printk(KERN_ERR "/proc/device-tree: can't find root\n");
+ return;
+ }
+ proc_device_tree_add_node(root, proc_device_tree);
+ of_node_put(root);
+}