Remove device_root device; replace with global_device_list.

The device_root device was only a placeholder device that provided a head
for the global device list, and a parent directory for root bridge devices.

This removes the device and replaces with an explicit global_device_list 
and a separate root directory. We never used any of the other fields in 
device_root, and we special cased it. So, it's better off dead.

drivers/base/base.h

@@ -6,7 +6,7 @@
 # define DBG(x...)
 #endif
 
-extern struct device device_root;
+extern struct list_head global_device_list;
 extern spinlock_t device_lock;
 
 extern struct device * get_device_locked(struct device *);

drivers/base/core.c

@@ -15,10 +15,7 @@
 #include <linux/err.h>
 #include "base.h"
 
-struct device device_root = {
-	.bus_id		= "root",
-	.name		= "System root",
-};
+LIST_HEAD(global_device_list);
 
 int (*platform_notify)(struct device * dev) = NULL;
 int (*platform_notify_remove)(struct device * dev) = NULL;
@@ -179,16 +176,14 @@ int device_register(struct device *dev)
 	spin_lock_init(&dev->lock);
 	atomic_set(&dev->refcount,2);
 	
-	if (dev != &device_root) {
-		if (!dev->parent)
-			dev->parent = &device_root;
-		get_device(dev->parent);
-
 	spin_lock(&device_lock);
+	if (dev->parent) {
+		get_device_locked(dev->parent);
 		list_add_tail(&dev->g_list,&dev->parent->g_list);
 		list_add_tail(&dev->node,&dev->parent->children);
+	} else
+		list_add_tail(&dev->g_list,&global_device_list);
 	spin_unlock(&device_lock);
-	}
 
 	pr_debug("DEV: registering device: ID = '%s', name = %s\n",
 		 dev->bus_id, dev->name);
@@ -269,27 +264,18 @@ void put_device(struct device * dev)
 	if (dev->release)
 		dev->release(dev);
 
+	if (dev->parent)
 		put_device(dev->parent);
 }
 
-static int __init device_init_root(void)
-{
-	return device_register(&device_root);
-}
-
 static int __init device_init(void)
 {
 	int error;
 
 	error = init_driverfs_fs();
-	if (error) {
-		panic("DEV: could not initialize driverfs");
-		return error;
-	}
-	error = device_init_root();
 	if (error)
-		printk(KERN_ERR "%s: device root init failed!\n", __FUNCTION__);
-	return error;
+		panic("DEV: could not initialize driverfs");
+	return 0;
 }
 
 core_initcall(device_init);

drivers/base/fs/device.c

@@ -10,11 +10,17 @@
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/string.h>
+#include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/stat.h>
 #include <linux/limits.h>
 
+static struct driver_dir_entry device_root_dir = {
+	.name	= "root",
+	.mode	= (S_IRWXU | S_IRUGO | S_IXUGO),
+};
+
 extern struct device_attribute * device_default_files[];
 
 #define to_dev_attr(_attr) container_of(_attr,struct device_attribute,attr)
@@ -164,7 +170,7 @@ int device_bus_link(struct device * dev)
 	 * one to get to the 'bus' directory, and one to get to the root 
 	 * of the fs.)
 	 */
-	length += strlen("../../..");
+	length += strlen("../../../root");
 
 	if (length > PATH_MAX)
 		return -ENAMETOOLONG;
@@ -174,7 +180,7 @@ int device_bus_link(struct device * dev)
 	memset(path,0,length);
 
 	/* our relative position */
-	strcpy(path,"../../..");
+	strcpy(path,"../../../root");
 
 	fill_devpath(dev,path,length);
 	error = driverfs_create_symlink(&dev->bus->device_dir,dev->bus_id,path);
@@ -207,13 +213,12 @@ int device_create_dir(struct driver_dir_entry * dir, struct driver_dir_entry * p
  */
 int device_make_dir(struct device * dev)
 {
-	struct driver_dir_entry * parent = NULL;
+	struct driver_dir_entry * parent;
 	struct device_attribute * entry;
 	int error;
 	int i;
 
-	if (dev->parent)
-		parent = &dev->parent->dir;
+	parent = dev->parent ? &dev->parent->dir : &device_root_dir;
 	dev->dir.name = dev->bus_id;
 	dev->dir.ops = &dev_attr_ops;
 
@@ -229,5 +234,12 @@ int device_make_dir(struct device * dev)
 	return error;
 }
 
+static int device_driverfs_init(void)
+{
+	return driverfs_create_dir(&device_root_dir,NULL);
+}
+
+core_initcall(device_driverfs_init);
+
 EXPORT_SYMBOL(device_create_file);
 EXPORT_SYMBOL(device_remove_file);

drivers/base/power.c

@@ -34,7 +34,7 @@ int device_suspend(u32 state, u32 level)
 	printk(KERN_EMERG "Suspending Devices\n");
 
 	spin_lock(&device_lock);
-	list_for_each(node,&device_root.g_list) {
+	list_for_each(node,&global_device_list) {
 		struct device * dev = get_device_locked(to_dev(node));
 		if (dev) {
 			spin_unlock(&device_lock);
@@ -65,7 +65,7 @@ void device_resume(u32 level)
 	struct device * prev = NULL;
 
 	spin_lock(&device_lock);
-	list_for_each_prev(node,&device_root.g_list) {
+	list_for_each_prev(node,&global_device_list) {
 		struct device * dev = get_device_locked(to_dev(node));
 		if (dev) {
 			spin_unlock(&device_lock);
@@ -98,7 +98,7 @@ void device_shutdown(void)
 	printk(KERN_EMERG "Shutting down devices\n");
 
 	spin_lock(&device_lock);
-	list_for_each(node,&device_root.g_list) {
+	list_for_each(node,&global_device_list) {
 		struct device * dev = get_device_locked(to_dev(node));
 		if (dev) {
 			spin_unlock(&device_lock);