patch-2.1.51 linux/fs/proc/proc_devtree.c

• Lines: 220
• Date: Sat Aug 16 09:53:08 1997
• Orig file: v2.1.50/linux/fs/proc/proc_devtree.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.50/linux/fs/proc/proc_devtree.c linux/fs/proc/proc_devtree.c
@@ -0,0 +1,219 @@
+/*
+ * proc_devtree.c - handles /proc/device-tree
+ *
+ * Copyright 1997 Paul Mackerras
+ */
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <asm/prom.h>
+#include <asm/uaccess.h>
+
+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.
+ */
+
+static int devtree_readlink(struct inode *, char *, int);
+static struct dentry *devtree_follow_link(struct inode *, struct dentry *);
+
+struct inode_operations devtree_symlink_inode_operations = {
+	NULL,			/* no file-operations */
+	NULL,			/* create */
+	NULL,			/* lookup */
+	NULL,			/* link */
+	NULL,			/* unlink */
+	NULL,			/* symlink */
+	NULL,			/* mkdir */
+	NULL,			/* rmdir */
+	NULL,			/* mknod */
+	NULL,			/* rename */
+	devtree_readlink,	/* readlink */
+	devtree_follow_link,	/* follow_link */
+	NULL,			/* readpage */
+	NULL,			/* writepage */
+	NULL,			/* bmap */
+	NULL,			/* truncate */
+	NULL,			/* permission */
+	NULL			/* smap */
+};
+
+static struct dentry *devtree_follow_link(struct inode *inode,
+					  struct dentry *base)
+{
+	struct proc_dir_entry * de;
+	char *link;
+
+	de = (struct proc_dir_entry *) inode->u.generic_ip;
+	link = (char *) de->data;
+	return lookup_dentry(link, base, 1);
+}
+
+static int devtree_readlink(struct inode *inode, char *buffer, int buflen)
+{
+	struct proc_dir_entry * de;
+	char *link;
+	int linklen;
+
+	de = (struct proc_dir_entry *) inode->u.generic_ip;
+	link = (char *) de->data;
+	linklen = strlen(link);
+	if (linklen > buflen)
+		linklen = buflen;
+	if (copy_to_user(buffer, link, linklen))
+		return -EFAULT;
+	return linklen;
+}
+
+/*
+ * Process a node, adding entries for its children and its properties.
+ */
+static void 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;
+
+	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 = kmalloc(sizeof(struct proc_dir_entry), GFP_KERNEL);
+		if (ent == 0)
+			break;
+		memset(ent, 0, sizeof(struct proc_dir_entry));
+		ent->name = pp->name;
+		ent->namelen = strlen(pp->name);
+		ent->mode = S_IFREG | S_IRUGO;
+		ent->nlink = 1;
+		ent->data = pp;
+		ent->read_proc = property_read_proc;
+		ent->size = pp->length;
+		proc_register(de, ent);
+		*lastp = ent;
+		lastp = &ent->next;
+	}
+	for (child = np->child; child != 0; child = child->sibling) {
+		p = strrchr(child->full_name, '/');
+		if (p == 0)
+			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 = kmalloc(sizeof(struct proc_dir_entry), GFP_KERNEL);
+		if (ent == 0)
+			break;
+		memset(ent, 0, sizeof(struct proc_dir_entry));
+		ent->name = p;
+		ent->namelen = l;
+		ent->mode = S_IFDIR | S_IRUGO | S_IXUGO;
+		ent->nlink = 2;
+		proc_register(de, ent);
+		*lastp = ent;
+		lastp = &ent->next;
+		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.
+		 */
+		for (sib = np->child; sib != child; sib = sib->sibling)
+			if (strcmp(sib->name, child->name) == 0)
+				break;
+		if (sib == child && strncmp(p, child->name, l) != 0) {
+			al = kmalloc(sizeof(struct proc_dir_entry),
+				     GFP_KERNEL);
+			if (al == 0)
+				break;
+			memset(al, 0, sizeof(struct proc_dir_entry));
+			al->name = child->name;
+			al->namelen = strlen(child->name);
+			al->mode = S_IFLNK | S_IRUGO | S_IXUGO;
+			al->nlink = 1;
+			al->data = (void *) ent->name;
+			al->ops = &devtree_symlink_inode_operations;
+			proc_register(de, al);
+			*lastp = al;
+			lastp = &al->next;
+		}
+
+		/*
+		 * Add another directory with the @address part as its name.
+		 */
+		al = kmalloc(sizeof(struct proc_dir_entry), GFP_KERNEL);
+		if (al == 0)
+			break;
+		memset(al, 0, sizeof(struct proc_dir_entry));
+		al->name = at;
+		al->namelen = strlen(at);
+		al->mode = S_IFLNK | S_IRUGO | S_IXUGO;
+		al->nlink = 1;
+		al->data = (void *) ent->name;
+		al->ops = &devtree_symlink_inode_operations;
+		proc_register(de, al);
+		*lastp = al;
+		lastp = &al->next;
+	}
+	*lastp = 0;
+	de->subdir = list;
+}
+
+/*
+ * Called on initialization to set up the /proc/device-tree subtree
+ */
+void proc_device_tree_init(void)
+{
+	struct device_node *root;
+
+	proc_device_tree = create_proc_entry("device-tree", S_IFDIR, 0);
+	if (proc_device_tree == 0)
+		return;
+	root = find_path_device("/");
+	if (root == 0) {
+		printk(KERN_ERR "/proc/device-tree: can't find root\n");
+		return;
+	}
+	add_node(root, proc_device_tree);
+}