of: remove /proc/device-tree

The same data is now available in sysfs, so we can remove the code
that exports it in /proc and replace it with a symlink to the sysfs
version.

Tested on versatile qemu model and mpc5200 eval board. More testing
would be appreciated.

v5: Fixed up conflicts with mainline changes
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Pantelis Antoniou <panto@antoniou-consulting.com>

drivers/of/Kconfig

@@ -7,14 +7,6 @@ config OF
 menu "Device Tree and Open Firmware support"
 	depends on OF
 
-config PROC_DEVICETREE
-	bool "Support for device tree in /proc"
-	depends on PROC_FS && !SPARC
-	help
-	  This option adds a device-tree directory under /proc which contains
-	  an image of the device tree that the kernel copies from Open
-	  Firmware or other boot firmware. If unsure, say Y here.
-
 config OF_SELFTEST
 	bool "Device Tree Runtime self tests"
 	depends on OF_IRQ

drivers/of/base.c

@@ -281,11 +281,9 @@ static int __init of_init(void)
 		__of_node_add(np);
 	mutex_unlock(&of_aliases_mutex);
 
-#if !defined(CONFIG_PROC_DEVICETREE)
-	/* Symlink to the new tree when PROC_DEVICETREE is disabled */
+	/* Symlink in /proc as required by userspace ABI */
 	if (of_allnodes)
 		proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
-#endif /* CONFIG_PROC_DEVICETREE */
 
 	return 0;
 }
@@ -1690,12 +1688,6 @@ int of_add_property(struct device_node *np, struct property *prop)
 
 	__of_add_property_sysfs(np, prop);
 
-#ifdef CONFIG_PROC_DEVICETREE
-	/* try to add to proc as well if it was initialized */
-	if (!rc && np->pde)
-		proc_device_tree_add_prop(np->pde, prop);
-#endif /* CONFIG_PROC_DEVICETREE */
-
 	return rc;
 }
 
@@ -1742,12 +1734,6 @@ int of_remove_property(struct device_node *np, struct property *prop)
 
 	sysfs_remove_bin_file(&np->kobj, &prop->attr);
 
-#ifdef CONFIG_PROC_DEVICETREE
-	/* try to remove the proc node as well */
-	if (np->pde)
-		proc_device_tree_remove_prop(np->pde, prop);
-#endif /* CONFIG_PROC_DEVICETREE */
-
 	return 0;
 }
 
@@ -1803,12 +1789,6 @@ int of_update_property(struct device_node *np, struct property *newprop)
 	if (!found)
 		return -ENODEV;
 
-#ifdef CONFIG_PROC_DEVICETREE
-	/* try to add to proc as well if it was initialized */
-	if (np->pde)
-		proc_device_tree_update_prop(np->pde, newprop, oldprop);
-#endif /* CONFIG_PROC_DEVICETREE */
-
 	return 0;
 }
 
@@ -1843,22 +1823,6 @@ int of_reconfig_notify(unsigned long action, void *p)
 	return notifier_to_errno(rc);
 }
 
-#ifdef CONFIG_PROC_DEVICETREE
-static void of_add_proc_dt_entry(struct device_node *dn)
-{
-	struct proc_dir_entry *ent;
-
-	ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
-	if (ent)
-		proc_device_tree_add_node(dn, ent);
-}
-#else
-static void of_add_proc_dt_entry(struct device_node *dn)
-{
-	return;
-}
-#endif
-
 /**
  * of_attach_node - Plug a device node into the tree and global list.
  */
@@ -1880,22 +1844,9 @@ int of_attach_node(struct device_node *np)
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
 	of_node_add(np);
-	of_add_proc_dt_entry(np);
 	return 0;
 }
 
-#ifdef CONFIG_PROC_DEVICETREE
-static void of_remove_proc_dt_entry(struct device_node *dn)
-{
-	proc_remove(dn->pde);
-}
-#else
-static void of_remove_proc_dt_entry(struct device_node *dn)
-{
-	return;
-}
-#endif
-
 /**
  * of_detach_node - "Unplug" a node from the device tree.
  *
@@ -1951,7 +1902,6 @@ int of_detach_node(struct device_node *np)
 	of_node_set_flag(np, OF_DETACHED);
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
-	of_remove_proc_dt_entry(np);
 	of_node_remove(np);
 	return rc;
 }

fs/proc/Makefile

@@ -27,6 +27,5 @@ proc-$(CONFIG_PROC_SYSCTL)	+= proc_sysctl.o
 proc-$(CONFIG_NET)		+= proc_net.o
 proc-$(CONFIG_PROC_KCORE)	+= kcore.o
 proc-$(CONFIG_PROC_VMCORE)	+= vmcore.o
-proc-$(CONFIG_PROC_DEVICETREE)	+= proc_devtree.o
 proc-$(CONFIG_PRINTK)	+= kmsg.o
 proc-$(CONFIG_PROC_PAGE_MONITOR)	+= page.o

fs/proc/internal.h

@@ -210,13 +210,6 @@ extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry
 extern int proc_fill_super(struct super_block *);
 extern void proc_entry_rundown(struct proc_dir_entry *);
 
-/*
- * proc_devtree.c
- */
-#ifdef CONFIG_PROC_DEVICETREE
-extern void proc_device_tree_init(void);
-#endif
-
 /*
  * proc_namespaces.c
  */

fs/proc/proc_devtree.c

-/*
- * 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);
-}

fs/proc/root.c

@@ -183,9 +183,6 @@ void __init proc_root_init(void)
 	proc_mkdir("openprom", NULL);
 #endif
 	proc_tty_init();
-#ifdef CONFIG_PROC_DEVICETREE
-	proc_device_tree_init();
-#endif
 	proc_mkdir("bus", NULL);
 	proc_sys_init();
 }

include/linux/of.h

@@ -57,7 +57,6 @@ struct device_node {
 	struct	device_node *sibling;
 	struct	device_node *next;	/* next device of same type */
 	struct	device_node *allnext;	/* next in list of all nodes */
-	struct	proc_dir_entry *pde;	/* this node's proc directory */
 	struct	kobject kobj;
 	unsigned long _flags;
 	void	*data;
@@ -658,14 +657,4 @@ static inline int of_get_available_child_count(const struct device_node *np)
 	return num;
 }
 
-#if defined(CONFIG_PROC_FS) && defined(CONFIG_PROC_DEVICETREE)
-extern void proc_device_tree_add_node(struct device_node *, struct proc_dir_entry *);
-extern void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop);
-extern void proc_device_tree_remove_prop(struct proc_dir_entry *pde,
-					 struct property *prop);
-extern void proc_device_tree_update_prop(struct proc_dir_entry *pde,
-					 struct property *newprop,
-					 struct property *oldprop);
-#endif
-
 #endif /* _LINUX_OF_H */