/* * 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_FIXUPSstatic inline void set_node_proc_entry(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. */ /* * Add a property to a node */static struct proc_dir_entry *__proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp){	struct proc_dir_entry *ent; 	/*	 * 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 == NULL)		return NULL; 	if (!strncmp(pp->name, "security-", 9))		ent->size = 0; /* don't leak number of password chars */	else		ent->size = 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);} 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; 	for (ent = pde->subdir; ent != NULL; ent = ent->next)		if (ent->data == oldprop)			break;	if (ent == NULL) {		printk(KERN_WARNING "device-tree: property \"%s\" "		       " does not exist\n", oldprop->name);	} else {		ent->data = newprop;		ent->size = newprop->length;	}} /* * 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));) {		p = strrchr(child->full_name, '/');		if (!p)			p = child->full_name;		else			++p;		ent = proc_mkdir(p, de);		if (ent == 0)			break;		proc_device_tree_add_node(child, ent);	}	of_node_put(child);	for (pp = np->properties; pp != 0; pp = pp->next) {		/*		 * Yet another Apple device-tree bogosity: on some machines,		 * they have properties & nodes with the same name. Those		 * properties are quite unimportant for us though, thus we		 * simply "skip" them here, but we do have to check.		 */		for (ent = de->subdir; ent != NULL; ent = ent->next)			if (!strcmp(ent->name, pp->name))				break;		if (ent != NULL) {			printk(KERN_WARNING "device-tree: property \"%s\" name"			       " conflicts with node in %s\n", pp->name,			       np->full_name);			continue;		} 		ent = __proc_device_tree_add_prop(de, pp);		if (ent == 0)			break;	}} /* * 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);}