/* * proc_devtree.c - handles /proc/device-tree * * Copyright 1997 Paul Mackerras */#include <linux/errno.h>#include <linux/init.h>#include <linux/time.h>#include <linux/proc_fs.h>#include <linux/seq_file.h>#include <linux/printk.h>#include <linux/stat.h>#include <linux/string.h>#include <linux/of.h>#include <linux/export.h>#include <linux/slab.h>#include <asm/uaccess.h>#include "internal.h" static inline void set_node_proc_entry(struct device_node *np,				       struct proc_dir_entry *de){	np->pde = de;} static struct proc_dir_entry *proc_device_tree; /* * Supply data on a read from /proc/device-tree/node/property. */static int property_proc_show(struct seq_file *m, void *v){	struct property *pp = m->private; 	seq_write(m, pp->value, pp->length);	return 0;} static int property_proc_open(struct inode *inode, struct file *file){	return single_open(file, property_proc_show, __PDE_DATA(inode));} static const struct file_operations property_proc_fops = {	.owner		= THIS_MODULE,	.open		= property_proc_open,	.read		= seq_read,	.llseek		= seq_lseek,	.release	= single_release,}; /* * For a node with a name like "gc@10", we make symlinks called "gc" * and "@10" to it. */ /* * Add a property to a node */static struct proc_dir_entry *__proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp,		const char *name){	struct proc_dir_entry *ent; 	/*	 * Unfortunately proc_register puts each new entry	 * at the beginning of the list.  So we rearrange them.	 */	ent = proc_create_data(name,			       strncmp(name, "security-", 9) ? S_IRUGO : S_IRUSR,			       de, &property_proc_fops, pp);	if (ent == NULL)		return NULL; 	if (!strncmp(name, "security-", 9))		proc_set_size(ent, 0); /* don't leak number of password chars */	else		proc_set_size(ent, pp->length); 	return ent;}  void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop){	__proc_device_tree_add_prop(pde, prop, prop->name);} void proc_device_tree_remove_prop(struct proc_dir_entry *pde,				  struct property *prop){	remove_proc_entry(prop->name, pde);} void proc_device_tree_update_prop(struct proc_dir_entry *pde,				  struct property *newprop,				  struct property *oldprop){	struct proc_dir_entry *ent; 	if (!oldprop) {		proc_device_tree_add_prop(pde, newprop);		return;	} 	for (ent = pde->subdir; ent != NULL; ent = ent->next)		if (ent->data == oldprop)			break;	if (ent == NULL) {		pr_warn("device-tree: property \"%s\" does not exist\n",			oldprop->name);	} else {		ent->data = newprop;		ent->size = newprop->length;	}} /* * Various dodgy firmware might give us nodes and/or properties with * conflicting names. That's generally ok, except for exporting via /proc, * so munge names here to ensure they're unique. */ static int duplicate_name(struct proc_dir_entry *de, const char *name){	struct proc_dir_entry *ent;	int found = 0; 	spin_lock(&proc_subdir_lock); 	for (ent = de->subdir; ent != NULL; ent = ent->next) {		if (strcmp(ent->name, name) == 0) {			found = 1;			break;		}	} 	spin_unlock(&proc_subdir_lock); 	return found;} static const char *fixup_name(struct device_node *np, struct proc_dir_entry *de,		const char *name){	char *fixed_name;	int fixup_len = strlen(name) + 2 + 1; /* name + #x + \0 */	int i = 1, size; realloc:	fixed_name = kmalloc(fixup_len, GFP_KERNEL);	if (fixed_name == NULL) {		pr_err("device-tree: Out of memory trying to fixup "		       "name \"%s\"\n", name);		return name;	} retry:	size = snprintf(fixed_name, fixup_len, "%s#%d", name, i);	size++; /* account for NULL */ 	if (size > fixup_len) {		/* We ran out of space, free and reallocate. */		kfree(fixed_name);		fixup_len = size;		goto realloc;	} 	if (duplicate_name(de, fixed_name)) {		/* Multiple duplicates. Retry with a different offset. */		i++;		goto retry;	} 	pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",		np->full_name, fixed_name); 	return fixed_name;} /* * 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;	const char *p; 	set_node_proc_entry(np, de);	for (child = NULL; (child = of_get_next_child(np, child));) {		/* Use everything after the last slash, or the full name */		p = kbasename(child->full_name); 		if (duplicate_name(de, p))			p = fixup_name(np, de, p); 		ent = proc_mkdir(p, de);		if (ent == NULL)			break;		proc_device_tree_add_node(child, ent);	}	of_node_put(child); 	for (pp = np->properties; pp != NULL; pp = pp->next) {		p = pp->name; 		if (strchr(p, '/'))			continue; 		if (duplicate_name(de, p))			p = fixup_name(np, de, p); 		ent = __proc_device_tree_add_prop(de, pp, p);		if (ent == NULL)			break;	}} /* * Called on initialization to set up the /proc/device-tree subtree */void __init proc_device_tree_init(void){	struct device_node *root; 	proc_device_tree = proc_mkdir("device-tree", NULL);	if (proc_device_tree == NULL)		return;	root = of_find_node_by_path("/");	if (root == NULL) {		remove_proc_entry("device-tree", NULL);		pr_debug("/proc/device-tree: can't find root\n");		return;	}	proc_device_tree_add_node(root, proc_device_tree);	of_node_put(root);}