X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fbase%2Fbus.c;h=472810f8e6e7332f13127b31a299f5712e4ffbc9;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=b40af6a72afe35449978916b753ac5da27635619;hpb=9213980e6a70d8473e0ffd4b39ab5b6caaba9ff5;p=linux-2.6.git

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index b40af6a72..472810f8e 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -3,12 +3,11 @@
  *
  * Copyright (c) 2002-3 Patrick Mochel
  * Copyright (c) 2002-3 Open Source Development Labs
- * 
+ *
  * This file is released under the GPLv2
  *
  */
 
-#include <linux/config.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/errno.h>
@@ -17,17 +16,14 @@
 #include "base.h"
 #include "power/power.h"
 
-#define to_dev(node) container_of(node,struct device,bus_list)
-#define to_drv(node) container_of(node,struct device_driver,kobj.entry)
-
-#define to_bus_attr(_attr) container_of(_attr,struct bus_attribute,attr)
-#define to_bus(obj) container_of(obj,struct bus_type,subsys.kset.kobj)
+#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
+#define to_bus(obj) container_of(obj, struct bus_type, subsys.kset.kobj)
 
 /*
  * sysfs bindings for drivers
  */
 
-#define to_drv_attr(_attr) container_of(_attr,struct driver_attribute,attr)
+#define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)
 #define to_driver(obj) container_of(obj, struct device_driver, kobj)
 
 
@@ -36,23 +32,23 @@ drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
 {
 	struct driver_attribute * drv_attr = to_drv_attr(attr);
 	struct device_driver * drv = to_driver(kobj);
-	ssize_t ret = 0;
+	ssize_t ret = -EIO;
 
 	if (drv_attr->show)
-		ret = drv_attr->show(drv,buf);
+		ret = drv_attr->show(drv, buf);
 	return ret;
 }
 
 static ssize_t
-drv_attr_store(struct kobject * kobj, struct attribute * attr, 
+drv_attr_store(struct kobject * kobj, struct attribute * attr,
 	       const char * buf, size_t count)
 {
 	struct driver_attribute * drv_attr = to_drv_attr(attr);
 	struct device_driver * drv = to_driver(kobj);
-	ssize_t ret = 0;
+	ssize_t ret = -EIO;
 
 	if (drv_attr->store)
-		ret = drv_attr->store(drv,buf,count);
+		ret = drv_attr->store(drv, buf, count);
 	return ret;
 }
 
@@ -65,7 +61,7 @@ static struct sysfs_ops driver_sysfs_ops = {
 static void driver_release(struct kobject * kobj)
 {
 	struct device_driver * drv = to_driver(kobj);
-	up(&drv->unload_sem);
+	complete(&drv->unloaded);
 }
 
 static struct kobj_type ktype_driver = {
@@ -87,12 +83,12 @@ bus_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
 	ssize_t ret = 0;
 
 	if (bus_attr->show)
-		ret = bus_attr->show(bus,buf);
+		ret = bus_attr->show(bus, buf);
 	return ret;
 }
 
 static ssize_t
-bus_attr_store(struct kobject * kobj, struct attribute * attr, 
+bus_attr_store(struct kobject * kobj, struct attribute * attr,
 	       const char * buf, size_t count)
 {
 	struct bus_attribute * bus_attr = to_bus_attr(attr);
@@ -100,7 +96,7 @@ bus_attr_store(struct kobject * kobj, struct attribute * attr,
 	ssize_t ret = 0;
 
 	if (bus_attr->store)
-		ret = bus_attr->store(bus,buf,count);
+		ret = bus_attr->store(bus, buf, count);
 	return ret;
 }
 
@@ -113,7 +109,7 @@ int bus_create_file(struct bus_type * bus, struct bus_attribute * attr)
 {
 	int error;
 	if (get_bus(bus)) {
-		error = sysfs_create_file(&bus->subsys.kset.kobj,&attr->attr);
+		error = sysfs_create_file(&bus->subsys.kset.kobj, &attr->attr);
 		put_bus(bus);
 	} else
 		error = -EINVAL;
@@ -123,7 +119,7 @@ int bus_create_file(struct bus_type * bus, struct bus_attribute * attr)
 void bus_remove_file(struct bus_type * bus, struct bus_attribute * attr)
 {
 	if (get_bus(bus)) {
-		sysfs_remove_file(&bus->subsys.kset.kobj,&attr->attr);
+		sysfs_remove_file(&bus->subsys.kset.kobj, &attr->attr);
 		put_bus(bus);
 	}
 }
@@ -133,7 +129,83 @@ static struct kobj_type ktype_bus = {
 
 };
 
-decl_subsys(bus,&ktype_bus,NULL);
+static decl_subsys(bus, &ktype_bus, NULL);
+
+
+#ifdef CONFIG_HOTPLUG
+
+/* Manually detach a device from its associated driver. */
+static int driver_helper(struct device *dev, void *data)
+{
+	const char *name = data;
+
+	if (strcmp(name, dev->bus_id) == 0)
+		return 1;
+	return 0;
+}
+
+static ssize_t driver_unbind(struct device_driver *drv,
+			     const char *buf, size_t count)
+{
+	struct bus_type *bus = get_bus(drv->bus);
+	struct device *dev;
+	int err = -ENODEV;
+
+	dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
+	if (dev && dev->driver == drv) {
+		if (dev->parent)	/* Needed for USB */
+			down(&dev->parent->sem);
+		device_release_driver(dev);
+		if (dev->parent)
+			up(&dev->parent->sem);
+		err = count;
+	}
+	put_device(dev);
+	put_bus(bus);
+	return err;
+}
+static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind);
+
+/*
+ * Manually attach a device to a driver.
+ * Note: the driver must want to bind to the device,
+ * it is not possible to override the driver's id table.
+ */
+static ssize_t driver_bind(struct device_driver *drv,
+			   const char *buf, size_t count)
+{
+	struct bus_type *bus = get_bus(drv->bus);
+	struct device *dev;
+	int err = -ENODEV;
+
+	dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
+	if (dev && dev->driver == NULL) {
+		if (dev->parent)	/* Needed for USB */
+			down(&dev->parent->sem);
+		down(&dev->sem);
+		err = driver_probe_device(drv, dev);
+		up(&dev->sem);
+		if (dev->parent)
+			up(&dev->parent->sem);
+
+		if (err > 0) 		/* success */
+			err = count;
+		else if (err == 0)	/* driver didn't accept device */
+			err = -ENODEV;
+	}
+	put_device(dev);
+	put_bus(bus);
+	return err;
+}
+static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind);
+
+#endif
+
+static struct device * next_device(struct klist_iter * i)
+{
+	struct klist_node * n = klist_next(i);
+	return n ? container_of(n, struct device, knode_bus) : NULL;
+}
 
 /**
  *	bus_for_each_dev - device iterator.
@@ -151,33 +223,67 @@ decl_subsys(bus,&ktype_bus,NULL);
  *
  *	NOTE: The device that returns a non-zero value is not retained
  *	in any way, nor is its refcount incremented. If the caller needs
- *	to retain this data, it should do, and increment the reference 
+ *	to retain this data, it should do, and increment the reference
  *	count in the supplied callback.
  */
-int bus_for_each_dev(struct bus_type * bus, struct device * start, 
+
+int bus_for_each_dev(struct bus_type * bus, struct device * start,
 		     void * data, int (*fn)(struct device *, void *))
 {
-	struct device *dev;
-	struct list_head * head;
+	struct klist_iter i;
+	struct device * dev;
 	int error = 0;
 
-	if (!(bus = get_bus(bus)))
+	if (!bus)
 		return -EINVAL;
 
-	head = &bus->devices.list;
-	dev = list_prepare_entry(start, head, bus_list);
+	klist_iter_init_node(&bus->klist_devices, &i,
+			     (start ? &start->knode_bus : NULL));
+	while ((dev = next_device(&i)) && !error)
+		error = fn(dev, data);
+	klist_iter_exit(&i);
+	return error;
+}
 
-	down_read(&bus->subsys.rwsem);
-	list_for_each_entry_continue(dev, head, bus_list) {
-		get_device(dev);
-		error = fn(dev,data);
-		put_device(dev);
-		if (error)
+/**
+ * bus_find_device - device iterator for locating a particular device.
+ * @bus: bus type
+ * @start: Device to begin with
+ * @data: Data to pass to match function
+ * @match: Callback function to check device
+ *
+ * This is similar to the bus_for_each_dev() function above, but it
+ * returns a reference to a device that is 'found' for later use, as
+ * determined by the @match callback.
+ *
+ * The callback should return 0 if the device doesn't match and non-zero
+ * if it does.  If the callback returns non-zero, this function will
+ * return to the caller and not iterate over any more devices.
+ */
+struct device * bus_find_device(struct bus_type *bus,
+				struct device *start, void *data,
+				int (*match)(struct device *, void *))
+{
+	struct klist_iter i;
+	struct device *dev;
+
+	if (!bus)
+		return NULL;
+
+	klist_iter_init_node(&bus->klist_devices, &i,
+			     (start ? &start->knode_bus : NULL));
+	while ((dev = next_device(&i)))
+		if (match(dev, data) && get_device(dev))
 			break;
-	}
-	up_read(&bus->subsys.rwsem);
-	put_bus(bus);
-	return error;
+	klist_iter_exit(&i);
+	return dev;
+}
+
+
+static struct device_driver * next_driver(struct klist_iter * i)
+{
+	struct klist_node * n = klist_next(i);
+	return n ? container_of(n, struct device_driver, knode_bus) : NULL;
 }
 
 /**
@@ -193,7 +299,7 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start,
  *	and return it. If @start is not NULL, we use it as the head
  *	of the list.
  *
- *	NOTE: we don't return the driver that returns a non-zero 
+ *	NOTE: we don't return the driver that returns a non-zero
  *	value, nor do we leave the reference count incremented for that
  *	driver. If the caller needs to know that info, it must set it
  *	in the callback. It must also be sure to increment the refcount
@@ -203,202 +309,74 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start,
 int bus_for_each_drv(struct bus_type * bus, struct device_driver * start,
 		     void * data, int (*fn)(struct device_driver *, void *))
 {
-	struct list_head * head;
-	struct device_driver *drv;
+	struct klist_iter i;
+	struct device_driver * drv;
 	int error = 0;
 
-	if(!(bus = get_bus(bus)))
+	if (!bus)
 		return -EINVAL;
 
-	head = &bus->drivers.list;
-	drv = list_prepare_entry(start, head, kobj.entry);
-
-	down_read(&bus->subsys.rwsem);
-	list_for_each_entry_continue(drv, head, kobj.entry) {
-		get_driver(drv);
-		error = fn(drv,data);
-		put_driver(drv);
-		if(error)
-			break;
-	}
-	up_read(&bus->subsys.rwsem);
-	put_bus(bus);
+	klist_iter_init_node(&bus->klist_drivers, &i,
+			     start ? &start->knode_bus : NULL);
+	while ((drv = next_driver(&i)) && !error)
+		error = fn(drv, data);
+	klist_iter_exit(&i);
 	return error;
 }
 
-/**
- *	device_bind_driver - bind a driver to one device.
- *	@dev:	device.
- *
- *	Allow manual attachment of a driver to a deivce.
- *	Caller must have already set @dev->driver.
- *
- *	Note that this does not modify the bus reference count 
- *	nor take the bus's rwsem. Please verify those are accounted 
- *	for before calling this. (It is ok to call with no other effort
- *	from a driver's probe() method.)
- */
-
-void device_bind_driver(struct device * dev)
+static int device_add_attrs(struct bus_type * bus, struct device * dev)
 {
-	pr_debug("bound device '%s' to driver '%s'\n",
-		 dev->bus_id,dev->driver->name);
-	list_add_tail(&dev->driver_list,&dev->driver->devices);
-	sysfs_create_link(&dev->driver->kobj,&dev->kobj,
-			  kobject_name(&dev->kobj));
-}
-
+	int error = 0;
+	int i;
 
-/**
- *	bus_match - check compatibility between device & driver.
- *	@dev:	device.
- *	@drv:	driver.
- *
- *	First, we call the bus's match function, which should compare
- *	the device IDs the driver supports with the device IDs of the 
- *	device. Note we don't do this ourselves because we don't know 
- *	the format of the ID structures, nor what is to be considered
- *	a match and what is not.
- *	
- *	If we find a match, we call @drv->probe(@dev) if it exists, and 
- *	call attach() above.
- */
-static int bus_match(struct device * dev, struct device_driver * drv)
-{
-	int error = -ENODEV;
-	if (dev->bus->match(dev,drv)) {
-		dev->driver = drv;
-		if (drv->probe) {
-			if ((error = drv->probe(dev))) {
-				dev->driver = NULL;
-				return error;
-			}
+	if (bus->dev_attrs) {
+		for (i = 0; attr_name(bus->dev_attrs[i]); i++) {
+			error = device_create_file(dev,&bus->dev_attrs[i]);
+			if (error)
+				goto Err;
 		}
-		device_bind_driver(dev);
-		error = 0;
 	}
+ Done:
 	return error;
+ Err:
+	while (--i >= 0)
+		device_remove_file(dev,&bus->dev_attrs[i]);
+	goto Done;
 }
 
 
-/**
- *	device_attach - try to attach device to a driver.
- *	@dev:	device.
- *
- *	Walk the list of drivers that the bus has and call bus_match() 
- *	for each pair. If a compatible pair is found, break out and return.
- */
-static int device_attach(struct device * dev)
-{
- 	struct bus_type * bus = dev->bus;
-	struct list_head * entry;
-	int error;
-
-	if (dev->driver) {
-		device_bind_driver(dev);
-		return 1;
-	}
-
-	if (bus->match) {
-		list_for_each(entry,&bus->drivers.list) {
-			struct device_driver * drv = to_drv(entry);
-			error = bus_match(dev,drv);
-			if (!error )  
-				/* success, driver matched */
-				return 1; 
-			if (error != -ENODEV) 
-				/* driver matched but the probe failed */
-				printk(KERN_WARNING 
-				    "%s: probe of %s failed with error %d\n",
-				    drv->name, dev->bus_id, error);
-		}
-	}
-
-	return 0;
-}
-
-
-/**
- *	driver_attach - try to bind driver to devices.
- *	@drv:	driver.
- *
- *	Walk the list of devices that the bus has on it and try to match
- *	the driver with each one.
- *	If bus_match() returns 0 and the @dev->driver is set, we've found
- *	a compatible pair.
- *
- *	Note that we ignore the -ENODEV error from bus_match(), since it's 
- *	perfectly valid for a driver not to bind to any devices.
- */
-void driver_attach(struct device_driver * drv)
+static void device_remove_attrs(struct bus_type * bus, struct device * dev)
 {
-	struct bus_type * bus = drv->bus;
-	struct list_head * entry;
-	int error;
-
-	if (!bus->match)
-		return;
+	int i;
 
-	list_for_each(entry,&bus->devices.list) {
-		struct device * dev = container_of(entry,struct device,bus_list);
-		if (!dev->driver) {
-			error = bus_match(dev,drv);
-			if (error && (error != -ENODEV))
-				/* driver matched but the probe failed */
-				printk(KERN_WARNING 
-				    "%s: probe of %s failed with error %d\n",
-				    drv->name, dev->bus_id, error);
-		}
+	if (bus->dev_attrs) {
+		for (i = 0; attr_name(bus->dev_attrs[i]); i++)
+			device_remove_file(dev,&bus->dev_attrs[i]);
 	}
 }
 
-
-/**
- *	device_release_driver - manually detach device from driver.
- *	@dev:	device.
- *
- *	Manually detach device from driver.
- *	Note that this is called without incrementing the bus
- *	reference count nor taking the bus's rwsem. Be sure that
- *	those are accounted for before calling this function.
- */
-
-void device_release_driver(struct device * dev)
+#ifdef CONFIG_SYSFS_DEPRECATED
+static int make_deprecated_bus_links(struct device *dev)
 {
-	struct device_driver * drv = dev->driver;
-	if (drv) {
-		sysfs_remove_link(&drv->kobj,kobject_name(&dev->kobj));
-		list_del_init(&dev->driver_list);
-		device_detach_shutdown(dev);
-		if (drv->remove)
-			drv->remove(dev);
-		dev->driver = NULL;
-	}
+	return sysfs_create_link(&dev->kobj,
+				 &dev->bus->subsys.kset.kobj, "bus");
 }
 
-
-/**
- *	driver_detach - detach driver from all devices it controls.
- *	@drv:	driver.
- */
-
-static void driver_detach(struct device_driver * drv)
+static void remove_deprecated_bus_links(struct device *dev)
 {
-	struct list_head * entry, * next;
-	list_for_each_safe(entry,next,&drv->devices) {
-		struct device * dev = container_of(entry,struct device,driver_list);
-		device_release_driver(dev);
-	}
-	
+	sysfs_remove_link(&dev->kobj, "bus");
 }
+#else
+static inline int make_deprecated_bus_links(struct device *dev) { return 0; }
+static inline void remove_deprecated_bus_links(struct device *dev) { }
+#endif
 
 /**
  *	bus_add_device - add device to bus
  *	@dev:	device being added
  *
  *	- Add the device to its bus's list of devices.
- *	- Try to attach to driver.
- *	- Create link to device's physical location.
+ *	- Create link to device's bus.
  */
 int bus_add_device(struct device * dev)
 {
@@ -406,16 +384,59 @@ int bus_add_device(struct device * dev)
 	int error = 0;
 
 	if (bus) {
-		down_write(&dev->bus->subsys.rwsem);
-		pr_debug("bus %s: add device %s\n",bus->name,dev->bus_id);
-		list_add_tail(&dev->bus_list,&dev->bus->devices.list);
-		device_attach(dev);
-		up_write(&dev->bus->subsys.rwsem);
-		sysfs_create_link(&bus->devices.kobj,&dev->kobj,dev->bus_id);
+		pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id);
+		error = device_add_attrs(bus, dev);
+		if (error)
+			goto out_put;
+		error = sysfs_create_link(&bus->devices.kobj,
+						&dev->kobj, dev->bus_id);
+		if (error)
+			goto out_id;
+		error = sysfs_create_link(&dev->kobj,
+				&dev->bus->subsys.kset.kobj, "subsystem");
+		if (error)
+			goto out_subsys;
+		error = make_deprecated_bus_links(dev);
+		if (error)
+			goto out_deprecated;
 	}
+	return 0;
+
+out_deprecated:
+	sysfs_remove_link(&dev->kobj, "subsystem");
+out_subsys:
+	sysfs_remove_link(&bus->devices.kobj, dev->bus_id);
+out_id:
+	device_remove_attrs(bus, dev);
+out_put:
+	put_bus(dev->bus);
 	return error;
 }
 
+/**
+ *	bus_attach_device - add device to bus
+ *	@dev:	device tried to attach to a driver
+ *
+ *	- Add device to bus's list of devices.
+ *	- Try to attach to driver.
+ */
+int bus_attach_device(struct device * dev)
+{
+	struct bus_type *bus = dev->bus;
+	int ret = 0;
+
+	if (bus) {
+		dev->is_registered = 1;
+		ret = device_attach(dev);
+		if (ret >= 0) {
+			klist_add_tail(&dev->knode_bus, &bus->klist_devices);
+			ret = 0;
+		} else
+			dev->is_registered = 0;
+	}
+	return ret;
+}
+
 /**
  *	bus_remove_device - remove device from bus
  *	@dev:	device to be removed
@@ -428,49 +449,127 @@ int bus_add_device(struct device * dev)
 void bus_remove_device(struct device * dev)
 {
 	if (dev->bus) {
-		sysfs_remove_link(&dev->bus->devices.kobj,dev->bus_id);
-		down_write(&dev->bus->subsys.rwsem);
-		pr_debug("bus %s: remove device %s\n",dev->bus->name,dev->bus_id);
+		sysfs_remove_link(&dev->kobj, "subsystem");
+		remove_deprecated_bus_links(dev);
+		sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id);
+		device_remove_attrs(dev->bus, dev);
+		if (dev->is_registered) {
+			dev->is_registered = 0;
+			klist_del(&dev->knode_bus);
+		}
+		pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id);
 		device_release_driver(dev);
-		list_del_init(&dev->bus_list);
-		up_write(&dev->bus->subsys.rwsem);
 		put_bus(dev->bus);
 	}
 }
 
+static int driver_add_attrs(struct bus_type * bus, struct device_driver * drv)
+{
+	int error = 0;
+	int i;
+
+	if (bus->drv_attrs) {
+		for (i = 0; attr_name(bus->drv_attrs[i]); i++) {
+			error = driver_create_file(drv, &bus->drv_attrs[i]);
+			if (error)
+				goto Err;
+		}
+	}
+ Done:
+	return error;
+ Err:
+	while (--i >= 0)
+		driver_remove_file(drv, &bus->drv_attrs[i]);
+	goto Done;
+}
+
+
+static void driver_remove_attrs(struct bus_type * bus, struct device_driver * drv)
+{
+	int i;
+
+	if (bus->drv_attrs) {
+		for (i = 0; attr_name(bus->drv_attrs[i]); i++)
+			driver_remove_file(drv, &bus->drv_attrs[i]);
+	}
+}
+
+#ifdef CONFIG_HOTPLUG
+/*
+ * Thanks to drivers making their tables __devinit, we can't allow manual
+ * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled.
+ */
+static int __must_check add_bind_files(struct device_driver *drv)
+{
+	int ret;
+
+	ret = driver_create_file(drv, &driver_attr_unbind);
+	if (ret == 0) {
+		ret = driver_create_file(drv, &driver_attr_bind);
+		if (ret)
+			driver_remove_file(drv, &driver_attr_unbind);
+	}
+	return ret;
+}
+
+static void remove_bind_files(struct device_driver *drv)
+{
+	driver_remove_file(drv, &driver_attr_bind);
+	driver_remove_file(drv, &driver_attr_unbind);
+}
+#else
+static inline int add_bind_files(struct device_driver *drv) { return 0; }
+static inline void remove_bind_files(struct device_driver *drv) {}
+#endif
 
 /**
  *	bus_add_driver - Add a driver to the bus.
  *	@drv:	driver.
  *
  */
-int bus_add_driver(struct device_driver * drv)
+int bus_add_driver(struct device_driver *drv)
 {
 	struct bus_type * bus = get_bus(drv->bus);
 	int error = 0;
 
-	if (bus) {
-		pr_debug("bus %s: add driver %s\n",bus->name,drv->name);
-		error = kobject_set_name(&drv->kobj,drv->name);
-		if (error) {
-			put_bus(bus);
-			return error;
-		}
-		drv->kobj.kset = &bus->drivers;
-		if ((error = kobject_register(&drv->kobj))) {
-			put_bus(bus);
-			return error;
-		}
-
-		down_write(&bus->subsys.rwsem);
-		driver_attach(drv);
-		up_write(&bus->subsys.rwsem);
-
+	if (!bus)
+		return 0;
+
+	pr_debug("bus %s: add driver %s\n", bus->name, drv->name);
+	error = kobject_set_name(&drv->kobj, "%s", drv->name);
+	if (error)
+		goto out_put_bus;
+	drv->kobj.kset = &bus->drivers;
+	if ((error = kobject_register(&drv->kobj)))
+		goto out_put_bus;
+
+	error = driver_attach(drv);
+	if (error)
+		goto out_unregister;
+	klist_add_tail(&drv->knode_bus, &bus->klist_drivers);
+	module_add_driver(drv->owner, drv);
+
+	error = driver_add_attrs(bus, drv);
+	if (error) {
+		/* How the hell do we get out of this pickle? Give up */
+		printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
+			__FUNCTION__, drv->name);
+	}
+	error = add_bind_files(drv);
+	if (error) {
+		/* Ditto */
+		printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
+			__FUNCTION__, drv->name);
 	}
+
+	return error;
+out_unregister:
+	kobject_unregister(&drv->kobj);
+out_put_bus:
+	put_bus(bus);
 	return error;
 }
 
-
 /**
  *	bus_remove_driver - delete driver from bus's knowledge.
  *	@drv:	driver.
@@ -482,51 +581,77 @@ int bus_add_driver(struct device_driver * drv)
 
 void bus_remove_driver(struct device_driver * drv)
 {
-	if (drv->bus) {
-		down_write(&drv->bus->subsys.rwsem);
-		pr_debug("bus %s: remove driver %s\n",drv->bus->name,drv->name);
-		driver_detach(drv);
-		up_write(&drv->bus->subsys.rwsem);
-		kobject_unregister(&drv->kobj);
-		put_bus(drv->bus);
-	}
+	if (!drv->bus)
+		return;
+
+	remove_bind_files(drv);
+	driver_remove_attrs(drv->bus, drv);
+	klist_remove(&drv->knode_bus);
+	pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name);
+	driver_detach(drv);
+	module_remove_driver(drv);
+	kobject_unregister(&drv->kobj);
+	put_bus(drv->bus);
 }
 
 
 /* Helper for bus_rescan_devices's iter */
-static int bus_rescan_devices_helper(struct device *dev, void *data)
+static int __must_check bus_rescan_devices_helper(struct device *dev,
+						void *data)
 {
-	int *count = data;
-
-	if (!dev->driver && device_attach(dev))
-		(*count)++;
-
-	return 0;
+	int ret = 0;
+
+	if (!dev->driver) {
+		if (dev->parent)	/* Needed for USB */
+			down(&dev->parent->sem);
+		ret = device_attach(dev);
+		if (dev->parent)
+			up(&dev->parent->sem);
+		if (ret > 0)
+			ret = 0;
+	}
+	return ret < 0 ? ret : 0;
 }
 
-
 /**
- *	bus_rescan_devices - rescan devices on the bus for possible drivers
- *	@bus:	the bus to scan.
+ * bus_rescan_devices - rescan devices on the bus for possible drivers
+ * @bus: the bus to scan.
  *
- *	This function will look for devices on the bus with no driver
- *	attached and rescan it against existing drivers to see if it
- *	matches any. Calls device_attach(). Returns the number of devices
- *	that were sucessfully bound to a driver.
+ * This function will look for devices on the bus with no driver
+ * attached and rescan it against existing drivers to see if it matches
+ * any by calling device_attach() for the unbound devices.
  */
 int bus_rescan_devices(struct bus_type * bus)
 {
-	int count = 0;
-
-	bus_for_each_dev(bus, NULL, &count, bus_rescan_devices_helper);
-
-	return count;
+	return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
 }
 
+/**
+ * device_reprobe - remove driver for a device and probe for a new driver
+ * @dev: the device to reprobe
+ *
+ * This function detaches the attached driver (if any) for the given
+ * device and restarts the driver probing process.  It is intended
+ * to use if probing criteria changed during a devices lifetime and
+ * driver attachment should change accordingly.
+ */
+int device_reprobe(struct device *dev)
+{
+	if (dev->driver) {
+		if (dev->parent)        /* Needed for USB */
+			down(&dev->parent->sem);
+		device_release_driver(dev);
+		if (dev->parent)
+			up(&dev->parent->sem);
+	}
+	return bus_rescan_devices_helper(dev, NULL);
+}
+EXPORT_SYMBOL_GPL(device_reprobe);
 
-struct bus_type * get_bus(struct bus_type * bus)
+struct bus_type *get_bus(struct bus_type *bus)
 {
-	return bus ? container_of(subsys_get(&bus->subsys),struct bus_type,subsys) : NULL;
+	return bus ? container_of(subsys_get(&bus->subsys),
+				struct bus_type, subsys) : NULL;
 }
 
 void put_bus(struct bus_type * bus)
@@ -541,13 +666,65 @@ void put_bus(struct bus_type * bus)
  *
  *	Call kset_find_obj() to iterate over list of buses to
  *	find a bus by name. Return bus if found.
+ *
+ *	Note that kset_find_obj increments bus' reference count.
  */
-
+#if 0
 struct bus_type * find_bus(char * name)
 {
-	struct kobject * k = kset_find_obj(&bus_subsys.kset,name);
+	struct kobject * k = kset_find_obj(&bus_subsys.kset, name);
 	return k ? to_bus(k) : NULL;
 }
+#endif  /*  0  */
+
+
+/**
+ *	bus_add_attrs - Add default attributes for this bus.
+ *	@bus:	Bus that has just been registered.
+ */
+
+static int bus_add_attrs(struct bus_type * bus)
+{
+	int error = 0;
+	int i;
+
+	if (bus->bus_attrs) {
+		for (i = 0; attr_name(bus->bus_attrs[i]); i++) {
+			if ((error = bus_create_file(bus,&bus->bus_attrs[i])))
+				goto Err;
+		}
+	}
+ Done:
+	return error;
+ Err:
+	while (--i >= 0)
+		bus_remove_file(bus,&bus->bus_attrs[i]);
+	goto Done;
+}
+
+static void bus_remove_attrs(struct bus_type * bus)
+{
+	int i;
+
+	if (bus->bus_attrs) {
+		for (i = 0; attr_name(bus->bus_attrs[i]); i++)
+			bus_remove_file(bus,&bus->bus_attrs[i]);
+	}
+}
+
+static void klist_devices_get(struct klist_node *n)
+{
+	struct device *dev = container_of(n, struct device, knode_bus);
+
+	get_device(dev);
+}
+
+static void klist_devices_put(struct klist_node *n)
+{
+	struct device *dev = container_of(n, struct device, knode_bus);
+
+	put_device(dev);
+}
 
 /**
  *	bus_register - register a bus with the system.
@@ -555,19 +732,21 @@ struct bus_type * find_bus(char * name)
  *
  *	Once we have that, we registered the bus with the kobject
  *	infrastructure, then register the children subsystems it has:
- *	the devices and drivers that belong to the bus. 
+ *	the devices and drivers that belong to the bus.
  */
 int bus_register(struct bus_type * bus)
 {
 	int retval;
 
-	retval = kobject_set_name(&bus->subsys.kset.kobj,bus->name);
+	BLOCKING_INIT_NOTIFIER_HEAD(&bus->bus_notifier);
+
+	retval = kobject_set_name(&bus->subsys.kset.kobj, "%s", bus->name);
 	if (retval)
 		goto out;
 
-	subsys_set_kset(bus,bus_subsys);
+	subsys_set_kset(bus, bus_subsys);
 	retval = subsystem_register(&bus->subsys);
-	if (retval) 
+	if (retval)
 		goto out;
 
 	kobject_set_name(&bus->devices.kobj, "devices");
@@ -583,9 +762,17 @@ int bus_register(struct bus_type * bus)
 	if (retval)
 		goto bus_drivers_fail;
 
-	pr_debug("bus type '%s' registered\n",bus->name);
+	klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put);
+	klist_init(&bus->klist_drivers, NULL, NULL);
+	retval = bus_add_attrs(bus);
+	if (retval)
+		goto bus_attrs_fail;
+
+	pr_debug("bus type '%s' registered\n", bus->name);
 	return 0;
 
+bus_attrs_fail:
+	kset_unregister(&bus->drivers);
 bus_drivers_fail:
 	kset_unregister(&bus->devices);
 bus_devices_fail:
@@ -596,7 +783,7 @@ out:
 
 
 /**
- *	bus_unregister - remove a bus from the system 
+ *	bus_unregister - remove a bus from the system
  *	@bus:	bus.
  *
  *	Unregister the child subsystems and the bus itself.
@@ -604,32 +791,38 @@ out:
  */
 void bus_unregister(struct bus_type * bus)
 {
-	pr_debug("bus %s: unregistering\n",bus->name);
+	pr_debug("bus %s: unregistering\n", bus->name);
+	bus_remove_attrs(bus);
 	kset_unregister(&bus->drivers);
 	kset_unregister(&bus->devices);
 	subsystem_unregister(&bus->subsys);
 }
 
+int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&bus->bus_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(bus_register_notifier);
+
+int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&bus->bus_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(bus_unregister_notifier);
+
 int __init buses_init(void)
 {
 	return subsystem_register(&bus_subsys);
 }
 
 
-EXPORT_SYMBOL(bus_for_each_dev);
-EXPORT_SYMBOL(bus_for_each_drv);
-
-EXPORT_SYMBOL(device_bind_driver);
-EXPORT_SYMBOL(device_release_driver);
+EXPORT_SYMBOL_GPL(bus_for_each_dev);
+EXPORT_SYMBOL_GPL(bus_find_device);
+EXPORT_SYMBOL_GPL(bus_for_each_drv);
 
-EXPORT_SYMBOL(bus_add_device);
-EXPORT_SYMBOL(bus_remove_device);
-EXPORT_SYMBOL(bus_register);
-EXPORT_SYMBOL(bus_unregister);
-EXPORT_SYMBOL(bus_rescan_devices);
-EXPORT_SYMBOL(get_bus);
-EXPORT_SYMBOL(put_bus);
-EXPORT_SYMBOL(find_bus);
+EXPORT_SYMBOL_GPL(bus_register);
+EXPORT_SYMBOL_GPL(bus_unregister);
+EXPORT_SYMBOL_GPL(bus_rescan_devices);
 
-EXPORT_SYMBOL(bus_create_file);
-EXPORT_SYMBOL(bus_remove_file);
+EXPORT_SYMBOL_GPL(bus_create_file);
+EXPORT_SYMBOL_GPL(bus_remove_file);