From fe6b91f47080eb17d21cbf2a39311877d57f6938 Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Tue, 6 Dec 2011 23:24:52 +0100
Subject: PM / Driver core: leave runtime PM enabled during system shutdown

Disabling all runtime PM during system shutdown turns out not to be a
good idea, because some devices may need to be woken up from a
low-power state at that time.

The whole point of disabling runtime PM for system shutdown was to
prevent untimely runtime-suspend method calls.  This patch (as1504)
accomplishes the same result by incrementing the usage count for each
device and waiting for ongoing runtime-PM callbacks to finish.  This
is what we already do during system suspend and hibernation, which
makes sense since the shutdown method is pretty much a legacy analog
of the pm->poweroff method.

This fixes a recent regression on some OMAP systems introduced by
commit af8db1508f2c9f3b6e633e2d2d906c6557c617f9 (PM / driver core:
disable device's runtime PM during shutdown).

Reported-and-tested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/base/core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/core.c b/drivers/base/core.c
index d8b3d89db043..919daa7cd5b1 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1743,8 +1743,10 @@ void device_shutdown(void)
 		 */
 		list_del_init(&dev->kobj.entry);
 		spin_unlock(&devices_kset->list_lock);
-		/* Disable all device's runtime power management */
-		pm_runtime_disable(dev);
+
+		/* Don't allow any more runtime suspends */
+		pm_runtime_get_noresume(dev);
+		pm_runtime_barrier(dev);
 
 		if (dev->bus && dev->bus->shutdown) {
 			dev_dbg(dev, "shutdown\n");
-- 
cgit v1.2.3


From ca22e56debc57b47c422b749c93217ba62644be2 Mon Sep 17 00:00:00 2001
From: Kay Sievers <kay.sievers@vrfy.org>
Date: Wed, 14 Dec 2011 14:29:38 -0800
Subject: driver-core: implement 'sysdev' functionality for regular devices and
 buses

All sysdev classes and sysdev devices will converted to regular devices
and buses to properly hook userspace into the event processing.

There is no interesting difference between a 'sysdev' and 'device' which
would justify to roll an entire own subsystem with different userspace
export semantics. Userspace relies on events and generic sysfs subsystem
infrastructure from sysdev devices, which are currently not properly
available.

Every converted sysdev class will create a regular device with the class
name in /sys/devices/system and all registered devices will becom a children
of theses devices.

For compatibility reasons, the sysdev class-wide attributes are created
at this parent device. (Do not copy that logic for anything new, subsystem-
wide properties belong to the subsystem, not to some fake parent device
created in /sys/devices.)

Every sysdev driver is implemented as a simple subsystem interface now,
and no longer called a driver.

After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/base/base.h    |  12 +-
 drivers/base/bus.c     | 293 +++++++++++++++++++++++++++++++++++++++++++++----
 drivers/base/class.c   |  14 +--
 drivers/base/core.c    |  85 +++++++++++---
 drivers/base/init.c    |   1 -
 drivers/base/sys.c     |  10 +-
 include/linux/device.h |  78 ++++++++++++-
 7 files changed, 431 insertions(+), 62 deletions(-)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/base.h b/drivers/base/base.h
index 21c1b96c34c6..7a6ae4228761 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -4,7 +4,9 @@
  * struct subsys_private - structure to hold the private to the driver core portions of the bus_type/class structure.
  *
  * @subsys - the struct kset that defines this subsystem
- * @devices_kset - the list of devices associated
+ * @devices_kset - the subsystem's 'devices' directory
+ * @interfaces - list of subsystem interfaces associated
+ * @mutex - protect the devices, and interfaces lists.
  *
  * @drivers_kset - the list of drivers associated
  * @klist_devices - the klist to iterate over the @devices_kset
@@ -14,10 +16,8 @@
  * @bus - pointer back to the struct bus_type that this structure is associated
  *        with.
  *
- * @class_interfaces - list of class_interfaces associated
  * @glue_dirs - "glue" directory to put in-between the parent device to
  *              avoid namespace conflicts
- * @class_mutex - mutex to protect the children, devices, and interfaces lists.
  * @class - pointer back to the struct class that this structure is associated
  *          with.
  *
@@ -28,6 +28,8 @@
 struct subsys_private {
 	struct kset subsys;
 	struct kset *devices_kset;
+	struct list_head interfaces;
+	struct mutex mutex;
 
 	struct kset *drivers_kset;
 	struct klist klist_devices;
@@ -36,9 +38,7 @@ struct subsys_private {
 	unsigned int drivers_autoprobe:1;
 	struct bus_type *bus;
 
-	struct list_head class_interfaces;
 	struct kset glue_dirs;
-	struct mutex class_mutex;
 	struct class *class;
 };
 #define to_subsys_private(obj) container_of(obj, struct subsys_private, subsys.kobj)
@@ -94,7 +94,6 @@ extern int hypervisor_init(void);
 static inline int hypervisor_init(void) { return 0; }
 #endif
 extern int platform_bus_init(void);
-extern int system_bus_init(void);
 extern int cpu_dev_init(void);
 
 extern int bus_add_device(struct device *dev);
@@ -116,6 +115,7 @@ extern char *make_class_name(const char *name, struct kobject *kobj);
 
 extern int devres_release_all(struct device *dev);
 
+/* /sys/devices directory */
 extern struct kset *devices_kset;
 
 #if defined(CONFIG_MODULES) && defined(CONFIG_SYSFS)
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 000e7b2006f8..99dc5921e1dd 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -16,9 +16,14 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/string.h>
+#include <linux/mutex.h>
 #include "base.h"
 #include "power/power.h"
 
+/* /sys/devices/system */
+/* FIXME: make static after drivers/base/sys.c is deleted */
+struct kset *system_kset;
+
 #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
 
 /*
@@ -360,6 +365,47 @@ struct device *bus_find_device_by_name(struct bus_type *bus,
 }
 EXPORT_SYMBOL_GPL(bus_find_device_by_name);
 
+/**
+ * subsys_find_device_by_id - find a device with a specific enumeration number
+ * @subsys: subsystem
+ * @id: index 'id' in struct device
+ * @hint: device to check first
+ *
+ * Check the hint's next object and if it is a match return it directly,
+ * otherwise, fall back to a full list search. Either way a reference for
+ * the returned object is taken.
+ */
+struct device *subsys_find_device_by_id(struct bus_type *subsys, unsigned int id,
+					struct device *hint)
+{
+	struct klist_iter i;
+	struct device *dev;
+
+	if (!subsys)
+		return NULL;
+
+	if (hint) {
+		klist_iter_init_node(&subsys->p->klist_devices, &i, &hint->p->knode_bus);
+		dev = next_device(&i);
+		if (dev && dev->id == id && get_device(dev)) {
+			klist_iter_exit(&i);
+			return dev;
+		}
+		klist_iter_exit(&i);
+	}
+
+	klist_iter_init_node(&subsys->p->klist_devices, &i, NULL);
+	while ((dev = next_device(&i))) {
+		if (dev->id == id && get_device(dev)) {
+			klist_iter_exit(&i);
+			return dev;
+		}
+	}
+	klist_iter_exit(&i);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(subsys_find_device_by_id);
+
 static struct device_driver *next_driver(struct klist_iter *i)
 {
 	struct klist_node *n = klist_next(i);
@@ -487,38 +533,59 @@ out_put:
 void bus_probe_device(struct device *dev)
 {
 	struct bus_type *bus = dev->bus;
+	struct subsys_interface *sif;
 	int ret;
 
-	if (bus && bus->p->drivers_autoprobe) {
+	if (!bus)
+		return;
+
+	if (bus->p->drivers_autoprobe) {
 		ret = device_attach(dev);
 		WARN_ON(ret < 0);
 	}
+
+	mutex_lock(&bus->p->mutex);
+	list_for_each_entry(sif, &bus->p->interfaces, node)
+		if (sif->add_dev)
+			sif->add_dev(dev, sif);
+	mutex_unlock(&bus->p->mutex);
 }
 
 /**
  * bus_remove_device - remove device from bus
  * @dev: device to be removed
  *
- * - Remove symlink from bus's directory.
+ * - Remove device from all interfaces.
+ * - Remove symlink from bus' directory.
  * - Delete device from bus's list.
  * - Detach from its driver.
  * - Drop reference taken in bus_add_device().
  */
 void bus_remove_device(struct device *dev)
 {
-	if (dev->bus) {
-		sysfs_remove_link(&dev->kobj, "subsystem");
-		sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
-				  dev_name(dev));
-		device_remove_attrs(dev->bus, dev);
-		if (klist_node_attached(&dev->p->knode_bus))
-			klist_del(&dev->p->knode_bus);
-
-		pr_debug("bus: '%s': remove device %s\n",
-			 dev->bus->name, dev_name(dev));
-		device_release_driver(dev);
-		bus_put(dev->bus);
-	}
+	struct bus_type *bus = dev->bus;
+	struct subsys_interface *sif;
+
+	if (!bus)
+		return;
+
+	mutex_lock(&bus->p->mutex);
+	list_for_each_entry(sif, &bus->p->interfaces, node)
+		if (sif->remove_dev)
+			sif->remove_dev(dev, sif);
+	mutex_unlock(&bus->p->mutex);
+
+	sysfs_remove_link(&dev->kobj, "subsystem");
+	sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
+			  dev_name(dev));
+	device_remove_attrs(dev->bus, dev);
+	if (klist_node_attached(&dev->p->knode_bus))
+		klist_del(&dev->p->knode_bus);
+
+	pr_debug("bus: '%s': remove device %s\n",
+		 dev->bus->name, dev_name(dev));
+	device_release_driver(dev);
+	bus_put(dev->bus);
 }
 
 static int driver_add_attrs(struct bus_type *bus, struct device_driver *drv)
@@ -847,14 +914,14 @@ static ssize_t bus_uevent_store(struct bus_type *bus,
 static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
 
 /**
- * bus_register - register a bus with the system.
+ * __bus_register - register a driver-core subsystem
  * @bus: bus.
  *
  * 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 subsystem.
  */
-int bus_register(struct bus_type *bus)
+int __bus_register(struct bus_type *bus, struct lock_class_key *key)
 {
 	int retval;
 	struct subsys_private *priv;
@@ -898,6 +965,8 @@ int bus_register(struct bus_type *bus)
 		goto bus_drivers_fail;
 	}
 
+	INIT_LIST_HEAD(&priv->interfaces);
+	__mutex_init(&priv->mutex, "subsys mutex", key);
 	klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
 	klist_init(&priv->klist_drivers, NULL, NULL);
 
@@ -927,7 +996,7 @@ out:
 	bus->p = NULL;
 	return retval;
 }
-EXPORT_SYMBOL_GPL(bus_register);
+EXPORT_SYMBOL_GPL(__bus_register);
 
 /**
  * bus_unregister - remove a bus from the system
@@ -939,6 +1008,8 @@ EXPORT_SYMBOL_GPL(bus_register);
 void bus_unregister(struct bus_type *bus)
 {
 	pr_debug("bus: '%s': unregistering\n", bus->name);
+	if (bus->dev_root)
+		device_unregister(bus->dev_root);
 	bus_remove_attrs(bus);
 	remove_probe_files(bus);
 	kset_unregister(bus->p->drivers_kset);
@@ -1028,10 +1099,194 @@ void bus_sort_breadthfirst(struct bus_type *bus,
 }
 EXPORT_SYMBOL_GPL(bus_sort_breadthfirst);
 
+/**
+ * subsys_dev_iter_init - initialize subsys device iterator
+ * @iter: subsys iterator to initialize
+ * @subsys: the subsys we wanna iterate over
+ * @start: the device to start iterating from, if any
+ * @type: device_type of the devices to iterate over, NULL for all
+ *
+ * Initialize subsys iterator @iter such that it iterates over devices
+ * of @subsys.  If @start is set, the list iteration will start there,
+ * otherwise if it is NULL, the iteration starts at the beginning of
+ * the list.
+ */
+void subsys_dev_iter_init(struct subsys_dev_iter *iter, struct bus_type *subsys,
+			  struct device *start, const struct device_type *type)
+{
+	struct klist_node *start_knode = NULL;
+
+	if (start)
+		start_knode = &start->p->knode_bus;
+	klist_iter_init_node(&subsys->p->klist_devices, &iter->ki, start_knode);
+	iter->type = type;
+}
+EXPORT_SYMBOL_GPL(subsys_dev_iter_init);
+
+/**
+ * subsys_dev_iter_next - iterate to the next device
+ * @iter: subsys iterator to proceed
+ *
+ * Proceed @iter to the next device and return it.  Returns NULL if
+ * iteration is complete.
+ *
+ * The returned device is referenced and won't be released till
+ * iterator is proceed to the next device or exited.  The caller is
+ * free to do whatever it wants to do with the device including
+ * calling back into subsys code.
+ */
+struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter)
+{
+	struct klist_node *knode;
+	struct device *dev;
+
+	for (;;) {
+		knode = klist_next(&iter->ki);
+		if (!knode)
+			return NULL;
+		dev = container_of(knode, struct device_private, knode_bus)->device;
+		if (!iter->type || iter->type == dev->type)
+			return dev;
+	}
+}
+EXPORT_SYMBOL_GPL(subsys_dev_iter_next);
+
+/**
+ * subsys_dev_iter_exit - finish iteration
+ * @iter: subsys iterator to finish
+ *
+ * Finish an iteration.  Always call this function after iteration is
+ * complete whether the iteration ran till the end or not.
+ */
+void subsys_dev_iter_exit(struct subsys_dev_iter *iter)
+{
+	klist_iter_exit(&iter->ki);
+}
+EXPORT_SYMBOL_GPL(subsys_dev_iter_exit);
+
+int subsys_interface_register(struct subsys_interface *sif)
+{
+	struct bus_type *subsys;
+	struct subsys_dev_iter iter;
+	struct device *dev;
+
+	if (!sif || !sif->subsys)
+		return -ENODEV;
+
+	subsys = bus_get(sif->subsys);
+	if (!subsys)
+		return -EINVAL;
+
+	mutex_lock(&subsys->p->mutex);
+	list_add_tail(&sif->node, &subsys->p->interfaces);
+	if (sif->add_dev) {
+		subsys_dev_iter_init(&iter, subsys, NULL, NULL);
+		while ((dev = subsys_dev_iter_next(&iter)))
+			sif->add_dev(dev, sif);
+		subsys_dev_iter_exit(&iter);
+	}
+	mutex_unlock(&subsys->p->mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(subsys_interface_register);
+
+void subsys_interface_unregister(struct subsys_interface *sif)
+{
+	struct bus_type *subsys = sif->subsys;
+	struct subsys_dev_iter iter;
+	struct device *dev;
+
+	if (!sif)
+		return;
+
+	mutex_lock(&subsys->p->mutex);
+	list_del_init(&sif->node);
+	if (sif->remove_dev) {
+		subsys_dev_iter_init(&iter, subsys, NULL, NULL);
+		while ((dev = subsys_dev_iter_next(&iter)))
+			sif->remove_dev(dev, sif);
+		subsys_dev_iter_exit(&iter);
+	}
+	mutex_unlock(&subsys->p->mutex);
+
+	bus_put(subsys);
+}
+EXPORT_SYMBOL_GPL(subsys_interface_unregister);
+
+static void system_root_device_release(struct device *dev)
+{
+	kfree(dev);
+}
+/**
+ * subsys_system_register - register a subsystem at /sys/devices/system/
+ * @subsys - system subsystem
+ * @groups - default attributes for the root device
+ *
+ * All 'system' subsystems have a /sys/devices/system/<name> root device
+ * with the name of the subsystem. The root device can carry subsystem-
+ * wide attributes. All registered devices are below this single root
+ * device and are named after the subsystem with a simple enumeration
+ * number appended. The registered devices are not explicitely named;
+ * only 'id' in the device needs to be set.
+ *
+ * Do not use this interface for anything new, it exists for compatibility
+ * with bad ideas only. New subsystems should use plain subsystems; and
+ * add the subsystem-wide attributes should be added to the subsystem
+ * directory itself and not some create fake root-device placed in
+ * /sys/devices/system/<name>.
+ */
+int subsys_system_register(struct bus_type *subsys,
+			   const struct attribute_group **groups)
+{
+	struct device *dev;
+	int err;
+
+	err = bus_register(subsys);
+	if (err < 0)
+		return err;
+
+	dev = kzalloc(sizeof(struct device), GFP_KERNEL);
+	if (!dev) {
+		err = -ENOMEM;
+		goto err_dev;
+	}
+
+	err = dev_set_name(dev, "%s", subsys->name);
+	if (err < 0)
+		goto err_name;
+
+	dev->kobj.parent = &system_kset->kobj;
+	dev->groups = groups;
+	dev->release = system_root_device_release;
+
+	err = device_register(dev);
+	if (err < 0)
+		goto err_dev_reg;
+
+	subsys->dev_root = dev;
+	return 0;
+
+err_dev_reg:
+	put_device(dev);
+	dev = NULL;
+err_name:
+	kfree(dev);
+err_dev:
+	bus_unregister(subsys);
+	return err;
+}
+EXPORT_SYMBOL_GPL(subsys_system_register);
+
 int __init buses_init(void)
 {
 	bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL);
 	if (!bus_kset)
 		return -ENOMEM;
+
+	system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
+	if (!system_kset)
+		return -ENOMEM;
+
 	return 0;
 }
diff --git a/drivers/base/class.c b/drivers/base/class.c
index b80d91cc8c3a..03243d4002fd 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -184,9 +184,9 @@ int __class_register(struct class *cls, struct lock_class_key *key)
 	if (!cp)
 		return -ENOMEM;
 	klist_init(&cp->klist_devices, klist_class_dev_get, klist_class_dev_put);
-	INIT_LIST_HEAD(&cp->class_interfaces);
+	INIT_LIST_HEAD(&cp->interfaces);
 	kset_init(&cp->glue_dirs);
-	__mutex_init(&cp->class_mutex, "struct class mutex", key);
+	__mutex_init(&cp->mutex, "subsys mutex", key);
 	error = kobject_set_name(&cp->subsys.kobj, "%s", cls->name);
 	if (error) {
 		kfree(cp);
@@ -460,15 +460,15 @@ int class_interface_register(struct class_interface *class_intf)
 	if (!parent)
 		return -EINVAL;
 
-	mutex_lock(&parent->p->class_mutex);
-	list_add_tail(&class_intf->node, &parent->p->class_interfaces);
+	mutex_lock(&parent->p->mutex);
+	list_add_tail(&class_intf->node, &parent->p->interfaces);
 	if (class_intf->add_dev) {
 		class_dev_iter_init(&iter, parent, NULL, NULL);
 		while ((dev = class_dev_iter_next(&iter)))
 			class_intf->add_dev(dev, class_intf);
 		class_dev_iter_exit(&iter);
 	}
-	mutex_unlock(&parent->p->class_mutex);
+	mutex_unlock(&parent->p->mutex);
 
 	return 0;
 }
@@ -482,7 +482,7 @@ void class_interface_unregister(struct class_interface *class_intf)
 	if (!parent)
 		return;
 
-	mutex_lock(&parent->p->class_mutex);
+	mutex_lock(&parent->p->mutex);
 	list_del_init(&class_intf->node);
 	if (class_intf->remove_dev) {
 		class_dev_iter_init(&iter, parent, NULL, NULL);
@@ -490,7 +490,7 @@ void class_interface_unregister(struct class_interface *class_intf)
 			class_intf->remove_dev(dev, class_intf);
 		class_dev_iter_exit(&iter);
 	}
-	mutex_unlock(&parent->p->class_mutex);
+	mutex_unlock(&parent->p->mutex);
 
 	class_put(parent);
 }
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 82c865452c70..a31ea193fba0 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -117,6 +117,56 @@ static const struct sysfs_ops dev_sysfs_ops = {
 	.store	= dev_attr_store,
 };
 
+#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
+
+ssize_t device_store_ulong(struct device *dev,
+			   struct device_attribute *attr,
+			   const char *buf, size_t size)
+{
+	struct dev_ext_attribute *ea = to_ext_attr(attr);
+	char *end;
+	unsigned long new = simple_strtoul(buf, &end, 0);
+	if (end == buf)
+		return -EINVAL;
+	*(unsigned long *)(ea->var) = new;
+	/* Always return full write size even if we didn't consume all */
+	return size;
+}
+EXPORT_SYMBOL_GPL(device_store_ulong);
+
+ssize_t device_show_ulong(struct device *dev,
+			  struct device_attribute *attr,
+			  char *buf)
+{
+	struct dev_ext_attribute *ea = to_ext_attr(attr);
+	return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
+}
+EXPORT_SYMBOL_GPL(device_show_ulong);
+
+ssize_t device_store_int(struct device *dev,
+			 struct device_attribute *attr,
+			 const char *buf, size_t size)
+{
+	struct dev_ext_attribute *ea = to_ext_attr(attr);
+	char *end;
+	long new = simple_strtol(buf, &end, 0);
+	if (end == buf || new > INT_MAX || new < INT_MIN)
+		return -EINVAL;
+	*(int *)(ea->var) = new;
+	/* Always return full write size even if we didn't consume all */
+	return size;
+}
+EXPORT_SYMBOL_GPL(device_store_int);
+
+ssize_t device_show_int(struct device *dev,
+			struct device_attribute *attr,
+			char *buf)
+{
+	struct dev_ext_attribute *ea = to_ext_attr(attr);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
+}
+EXPORT_SYMBOL_GPL(device_show_int);
 
 /**
  *	device_release - free device structure.
@@ -463,7 +513,7 @@ static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
 static struct device_attribute devt_attr =
 	__ATTR(dev, S_IRUGO, show_dev, NULL);
 
-/* kset to create /sys/devices/  */
+/* /sys/devices/ */
 struct kset *devices_kset;
 
 /**
@@ -710,6 +760,10 @@ static struct kobject *get_device_parent(struct device *dev,
 		return k;
 	}
 
+	/* subsystems can specify a default root directory for their devices */
+	if (!parent && dev->bus && dev->bus->dev_root)
+		return &dev->bus->dev_root->kobj;
+
 	if (parent)
 		return &parent->kobj;
 	return NULL;
@@ -730,14 +784,6 @@ static void cleanup_device_parent(struct device *dev)
 	cleanup_glue_dir(dev, dev->kobj.parent);
 }
 
-static void setup_parent(struct device *dev, struct device *parent)
-{
-	struct kobject *kobj;
-	kobj = get_device_parent(dev, parent);
-	if (kobj)
-		dev->kobj.parent = kobj;
-}
-
 static int device_add_class_symlinks(struct device *dev)
 {
 	int error;
@@ -890,6 +936,7 @@ int device_private_init(struct device *dev)
 int device_add(struct device *dev)
 {
 	struct device *parent = NULL;
+	struct kobject *kobj;
 	struct class_interface *class_intf;
 	int error = -EINVAL;
 
@@ -913,6 +960,10 @@ int device_add(struct device *dev)
 		dev->init_name = NULL;
 	}
 
+	/* subsystems can specify simple device enumeration */
+	if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
+		dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
+
 	if (!dev_name(dev)) {
 		error = -EINVAL;
 		goto name_error;
@@ -921,7 +972,9 @@ int device_add(struct device *dev)
 	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 
 	parent = get_device(dev->parent);
-	setup_parent(dev, parent);
+	kobj = get_device_parent(dev, parent);
+	if (kobj)
+		dev->kobj.parent = kobj;
 
 	/* use parent numa_node */
 	if (parent)
@@ -981,17 +1034,17 @@ int device_add(struct device *dev)
 			       &parent->p->klist_children);
 
 	if (dev->class) {
-		mutex_lock(&dev->class->p->class_mutex);
+		mutex_lock(&dev->class->p->mutex);
 		/* tie the class to the device */
 		klist_add_tail(&dev->knode_class,
 			       &dev->class->p->klist_devices);
 
 		/* notify any interfaces that the device is here */
 		list_for_each_entry(class_intf,
-				    &dev->class->p->class_interfaces, node)
+				    &dev->class->p->interfaces, node)
 			if (class_intf->add_dev)
 				class_intf->add_dev(dev, class_intf);
-		mutex_unlock(&dev->class->p->class_mutex);
+		mutex_unlock(&dev->class->p->mutex);
 	}
 done:
 	put_device(dev);
@@ -1106,15 +1159,15 @@ void device_del(struct device *dev)
 	if (dev->class) {
 		device_remove_class_symlinks(dev);
 
-		mutex_lock(&dev->class->p->class_mutex);
+		mutex_lock(&dev->class->p->mutex);
 		/* notify any interfaces that the device is now gone */
 		list_for_each_entry(class_intf,
-				    &dev->class->p->class_interfaces, node)
+				    &dev->class->p->interfaces, node)
 			if (class_intf->remove_dev)
 				class_intf->remove_dev(dev, class_intf);
 		/* remove the device from the class list */
 		klist_del(&dev->knode_class);
-		mutex_unlock(&dev->class->p->class_mutex);
+		mutex_unlock(&dev->class->p->mutex);
 	}
 	device_remove_file(dev, &uevent_attr);
 	device_remove_attrs(dev);
diff --git a/drivers/base/init.c b/drivers/base/init.c
index c8a934e79421..c16f0b808a17 100644
--- a/drivers/base/init.c
+++ b/drivers/base/init.c
@@ -31,7 +31,6 @@ void __init driver_init(void)
 	 * core core pieces.
 	 */
 	platform_bus_init();
-	system_bus_init();
 	cpu_dev_init();
 	memory_dev_init();
 }
diff --git a/drivers/base/sys.c b/drivers/base/sys.c
index 9dff77bfe1e3..409f5ce78829 100644
--- a/drivers/base/sys.c
+++ b/drivers/base/sys.c
@@ -126,7 +126,7 @@ void sysdev_class_remove_file(struct sysdev_class *c,
 }
 EXPORT_SYMBOL_GPL(sysdev_class_remove_file);
 
-static struct kset *system_kset;
+extern struct kset *system_kset;
 
 int sysdev_class_register(struct sysdev_class *cls)
 {
@@ -331,14 +331,6 @@ void sysdev_unregister(struct sys_device *sysdev)
 EXPORT_SYMBOL_GPL(sysdev_register);
 EXPORT_SYMBOL_GPL(sysdev_unregister);
 
-int __init system_bus_init(void)
-{
-	system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
-	if (!system_kset)
-		return -ENOMEM;
-	return 0;
-}
-
 #define to_ext_attr(x) container_of(x, struct sysdev_ext_attribute, attr)
 
 ssize_t sysdev_store_ulong(struct sys_device *sysdev,
diff --git a/include/linux/device.h b/include/linux/device.h
index 341fb740d851..7f9fc1505e94 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -53,6 +53,8 @@ extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
  * struct bus_type - The bus type of the device
  *
  * @name:	The name of the bus.
+ * @dev_name:	Used for subsystems to enumerate devices like ("foo%u", dev->id).
+ * @dev_root:	Default device to use as the parent.
  * @bus_attrs:	Default attributes of the bus.
  * @dev_attrs:	Default attributes of the devices on the bus.
  * @drv_attrs:	Default attributes of the device drivers on the bus.
@@ -86,6 +88,8 @@ extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
  */
 struct bus_type {
 	const char		*name;
+	const char		*dev_name;
+	struct device		*dev_root;
 	struct bus_attribute	*bus_attrs;
 	struct device_attribute	*dev_attrs;
 	struct driver_attribute	*drv_attrs;
@@ -106,12 +110,30 @@ struct bus_type {
 	struct subsys_private *p;
 };
 
-extern int __must_check bus_register(struct bus_type *bus);
+/* This is a #define to keep the compiler from merging different
+ * instances of the __key variable */
+#define bus_register(subsys)			\
+({						\
+	static struct lock_class_key __key;	\
+	__bus_register(subsys, &__key);	\
+})
+extern int __must_check __bus_register(struct bus_type *bus,
+				       struct lock_class_key *key);
 extern void bus_unregister(struct bus_type *bus);
 
 extern int __must_check bus_rescan_devices(struct bus_type *bus);
 
 /* iterator helpers for buses */
+struct subsys_dev_iter {
+	struct klist_iter		ki;
+	const struct device_type	*type;
+};
+void subsys_dev_iter_init(struct subsys_dev_iter *iter,
+			 struct bus_type *subsys,
+			 struct device *start,
+			 const struct device_type *type);
+struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
+void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
 
 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
 		     int (*fn)(struct device *dev, void *data));
@@ -121,10 +143,10 @@ struct device *bus_find_device(struct bus_type *bus, struct device *start,
 struct device *bus_find_device_by_name(struct bus_type *bus,
 				       struct device *start,
 				       const char *name);
-
+struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
+					struct device *hint);
 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
 		     void *data, int (*fn)(struct device_driver *, void *));
-
 void bus_sort_breadthfirst(struct bus_type *bus,
 			   int (*compare)(const struct device *a,
 					  const struct device *b));
@@ -255,6 +277,33 @@ struct device *driver_find_device(struct device_driver *drv,
 				  struct device *start, void *data,
 				  int (*match)(struct device *dev, void *data));
 
+/**
+ * struct subsys_interface - interfaces to device functions
+ * @name        name of the device function
+ * @subsystem   subsytem of the devices to attach to
+ * @node        the list of functions registered at the subsystem
+ * @add         device hookup to device function handler
+ * @remove      device hookup to device function handler
+ *
+ * Simple interfaces attached to a subsystem. Multiple interfaces can
+ * attach to a subsystem and its devices. Unlike drivers, they do not
+ * exclusively claim or control devices. Interfaces usually represent
+ * a specific functionality of a subsystem/class of devices.
+ */
+struct subsys_interface {
+	const char *name;
+	struct bus_type *subsys;
+	struct list_head node;
+	int (*add_dev)(struct device *dev, struct subsys_interface *sif);
+	int (*remove_dev)(struct device *dev, struct subsys_interface *sif);
+};
+
+int subsys_interface_register(struct subsys_interface *sif);
+void subsys_interface_unregister(struct subsys_interface *sif);
+
+int subsys_system_register(struct bus_type *subsys,
+			   const struct attribute_group **groups);
+
 /**
  * struct class - device classes
  * @name:	Name of the class.
@@ -438,8 +487,28 @@ struct device_attribute {
 			 const char *buf, size_t count);
 };
 
+struct dev_ext_attribute {
+	struct device_attribute attr;
+	void *var;
+};
+
+ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
+			  char *buf);
+ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t count);
+ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
+			char *buf);
+ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
+			 const char *buf, size_t count);
+
 #define DEVICE_ATTR(_name, _mode, _show, _store) \
-struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
+	struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
+#define DEVICE_ULONG_ATTR(_name, _mode, _var) \
+	struct dev_ext_attribute dev_attr_##_name = \
+		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
+#define DEVICE_INT_ATTR(_name, _mode, _var) \
+	struct dev_ext_attribute dev_attr_##_name = \
+		{ __ATTR(_name, _mode, device_show_ulong, device_store_ulong), &(_var) }
 
 extern int __must_check device_create_file(struct device *device,
 					const struct device_attribute *entry);
@@ -603,6 +672,7 @@ struct device {
 	struct device_node	*of_node; /* associated device tree node */
 
 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
+	u32			id;	/* device instance */
 
 	spinlock_t		devres_lock;
 	struct list_head	devres_head;
-- 
cgit v1.2.3


From 2c9ede55ecec58099b72e4bb8eab719f32f72c31 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 23 Jul 2011 20:24:48 -0400
Subject: switch device_get_devnode() and ->devnode() to umode_t *

both callers of device_get_devnode() are only interested in lower 16bits
and nobody tries to return anything wider than 16bit anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/x86/kernel/cpuid.c                    | 2 +-
 arch/x86/kernel/msr.c                      | 2 +-
 block/bsg.c                                | 2 +-
 block/genhd.c                              | 2 +-
 drivers/base/core.c                        | 4 ++--
 drivers/base/devtmpfs.c                    | 2 +-
 drivers/block/aoe/aoechr.c                 | 2 +-
 drivers/block/pktcdvd.c                    | 2 +-
 drivers/char/mem.c                         | 4 ++--
 drivers/char/misc.c                        | 2 +-
 drivers/char/raw.c                         | 2 +-
 drivers/char/tile-srom.c                   | 2 +-
 drivers/gpu/drm/drm_sysfs.c                | 2 +-
 drivers/hid/usbhid/hiddev.c                | 2 +-
 drivers/infiniband/core/cm.c               | 2 +-
 drivers/infiniband/core/user_mad.c         | 2 +-
 drivers/infiniband/core/uverbs_main.c      | 2 +-
 drivers/input/input.c                      | 2 +-
 drivers/media/dvb/ddbridge/ddbridge-core.c | 2 +-
 drivers/media/dvb/dvb-core/dvbdev.c        | 2 +-
 drivers/media/rc/rc-main.c                 | 2 +-
 drivers/tty/tty_io.c                       | 2 +-
 drivers/usb/class/usblp.c                  | 2 +-
 drivers/usb/core/file.c                    | 2 +-
 drivers/usb/core/usb.c                     | 2 +-
 drivers/usb/misc/iowarrior.c               | 2 +-
 drivers/usb/misc/legousbtower.c            | 2 +-
 include/linux/device.h                     | 6 +++---
 include/linux/genhd.h                      | 2 +-
 include/linux/usb.h                        | 2 +-
 sound/sound_core.c                         | 2 +-
 31 files changed, 35 insertions(+), 35 deletions(-)

(limited to 'drivers/base/core.c')

diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
index 212a6a42527c..a524353d93f2 100644
--- a/arch/x86/kernel/cpuid.c
+++ b/arch/x86/kernel/cpuid.c
@@ -177,7 +177,7 @@ static struct notifier_block __refdata cpuid_class_cpu_notifier =
 	.notifier_call = cpuid_class_cpu_callback,
 };
 
-static char *cpuid_devnode(struct device *dev, mode_t *mode)
+static char *cpuid_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "cpu/%u/cpuid", MINOR(dev->devt));
 }
diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
index 12fcbe2c143e..96356762a51d 100644
--- a/arch/x86/kernel/msr.c
+++ b/arch/x86/kernel/msr.c
@@ -236,7 +236,7 @@ static struct notifier_block __refdata msr_class_cpu_notifier = {
 	.notifier_call = msr_class_cpu_callback,
 };
 
-static char *msr_devnode(struct device *dev, mode_t *mode)
+static char *msr_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "cpu/%u/msr", MINOR(dev->devt));
 }
diff --git a/block/bsg.c b/block/bsg.c
index 702f1316bb8f..9651ec7b87c2 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -1070,7 +1070,7 @@ EXPORT_SYMBOL_GPL(bsg_register_queue);
 
 static struct cdev bsg_cdev;
 
-static char *bsg_devnode(struct device *dev, mode_t *mode)
+static char *bsg_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
 }
diff --git a/block/genhd.c b/block/genhd.c
index 02e9fca80825..80578f3176ef 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1109,7 +1109,7 @@ struct class block_class = {
 	.name		= "block",
 };
 
-static char *block_devnode(struct device *dev, mode_t *mode)
+static char *block_devnode(struct device *dev, umode_t *mode)
 {
 	struct gendisk *disk = dev_to_disk(dev);
 
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 919daa7cd5b1..1dfa1d616fa5 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -198,7 +198,7 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj,
 	if (MAJOR(dev->devt)) {
 		const char *tmp;
 		const char *name;
-		mode_t mode = 0;
+		umode_t mode = 0;
 
 		add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
 		add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
@@ -1182,7 +1182,7 @@ static struct device *next_device(struct klist_iter *i)
  * freed by the caller.
  */
 const char *device_get_devnode(struct device *dev,
-			       mode_t *mode, const char **tmp)
+			       umode_t *mode, const char **tmp)
 {
 	char *s;
 
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index a4760e095ff5..3990f682e690 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -40,7 +40,7 @@ static struct req {
 	struct completion done;
 	int err;
 	const char *name;
-	mode_t mode;	/* 0 => delete */
+	umode_t mode;	/* 0 => delete */
 	struct device *dev;
 } *requests;
 
diff --git a/drivers/block/aoe/aoechr.c b/drivers/block/aoe/aoechr.c
index 5f8e39c43ae5..e86d2062a164 100644
--- a/drivers/block/aoe/aoechr.c
+++ b/drivers/block/aoe/aoechr.c
@@ -270,7 +270,7 @@ static const struct file_operations aoe_fops = {
 	.llseek = noop_llseek,
 };
 
-static char *aoe_devnode(struct device *dev, mode_t *mode)
+static char *aoe_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "etherd/%s", dev_name(dev));
 }
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index a63b0a2b7805..d59edeabd93f 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2817,7 +2817,7 @@ static const struct block_device_operations pktcdvd_ops = {
 	.check_events =		pkt_check_events,
 };
 
-static char *pktcdvd_devnode(struct gendisk *gd, mode_t *mode)
+static char *pktcdvd_devnode(struct gendisk *gd, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "pktcdvd/%s", gd->disk_name);
 }
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 145179033716..d6e9d081c8b1 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -847,7 +847,7 @@ static const struct file_operations kmsg_fops = {
 
 static const struct memdev {
 	const char *name;
-	mode_t mode;
+	umode_t mode;
 	const struct file_operations *fops;
 	struct backing_dev_info *dev_info;
 } devlist[] = {
@@ -901,7 +901,7 @@ static const struct file_operations memory_fops = {
 	.llseek = noop_llseek,
 };
 
-static char *mem_devnode(struct device *dev, mode_t *mode)
+static char *mem_devnode(struct device *dev, umode_t *mode)
 {
 	if (mode && devlist[MINOR(dev->devt)].mode)
 		*mode = devlist[MINOR(dev->devt)].mode;
diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index 778273c93242..522136d40843 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -258,7 +258,7 @@ int misc_deregister(struct miscdevice *misc)
 EXPORT_SYMBOL(misc_register);
 EXPORT_SYMBOL(misc_deregister);
 
-static char *misc_devnode(struct device *dev, mode_t *mode)
+static char *misc_devnode(struct device *dev, umode_t *mode)
 {
 	struct miscdevice *c = dev_get_drvdata(dev);
 
diff --git a/drivers/char/raw.c b/drivers/char/raw.c
index b6de2c047145..54a3a6d09819 100644
--- a/drivers/char/raw.c
+++ b/drivers/char/raw.c
@@ -308,7 +308,7 @@ static const struct file_operations raw_ctl_fops = {
 
 static struct cdev raw_cdev;
 
-static char *raw_devnode(struct device *dev, mode_t *mode)
+static char *raw_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "raw/%s", dev_name(dev));
 }
diff --git a/drivers/char/tile-srom.c b/drivers/char/tile-srom.c
index cf3ee008dca2..4dc019408fac 100644
--- a/drivers/char/tile-srom.c
+++ b/drivers/char/tile-srom.c
@@ -329,7 +329,7 @@ static struct device_attribute srom_dev_attrs[] = {
 	__ATTR_NULL
 };
 
-static char *srom_devnode(struct device *dev, mode_t *mode)
+static char *srom_devnode(struct device *dev, umode_t *mode)
 {
 	*mode = S_IRUGO | S_IWUSR;
 	return kasprintf(GFP_KERNEL, "srom/%s", dev_name(dev));
diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
index 0f9ef9bf6730..62c3675045ac 100644
--- a/drivers/gpu/drm/drm_sysfs.c
+++ b/drivers/gpu/drm/drm_sysfs.c
@@ -72,7 +72,7 @@ static int drm_class_resume(struct device *dev)
 	return 0;
 }
 
-static char *drm_devnode(struct device *dev, mode_t *mode)
+static char *drm_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
 }
diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
index 4ef02b269a71..7c297d305d5d 100644
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -859,7 +859,7 @@ static const struct file_operations hiddev_fops = {
 	.llseek		= noop_llseek,
 };
 
-static char *hiddev_devnode(struct device *dev, mode_t *mode)
+static char *hiddev_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 }
diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 8b72f39202fb..c889aaef3416 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -3659,7 +3659,7 @@ static struct kobj_type cm_port_obj_type = {
 	.release = cm_release_port_obj
 };
 
-static char *cm_devnode(struct device *dev, mode_t *mode)
+static char *cm_devnode(struct device *dev, umode_t *mode)
 {
 	if (mode)
 		*mode = 0666;
diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index 07db22997e97..f0d588f8859e 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -1175,7 +1175,7 @@ static void ib_umad_remove_one(struct ib_device *device)
 	kref_put(&umad_dev->ref, ib_umad_release_dev);
 }
 
-static char *umad_devnode(struct device *dev, mode_t *mode)
+static char *umad_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
 }
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index 879636746373..604556d73d25 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -846,7 +846,7 @@ static void ib_uverbs_remove_one(struct ib_device *device)
 	kfree(uverbs_dev);
 }
 
-static char *uverbs_devnode(struct device *dev, mode_t *mode)
+static char *uverbs_devnode(struct device *dev, umode_t *mode)
 {
 	if (mode)
 		*mode = 0666;
diff --git a/drivers/input/input.c b/drivers/input/input.c
index da38d97a51b1..1f78c957a75a 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -1624,7 +1624,7 @@ static struct device_type input_dev_type = {
 #endif
 };
 
-static char *input_devnode(struct device *dev, mode_t *mode)
+static char *input_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev));
 }
diff --git a/drivers/media/dvb/ddbridge/ddbridge-core.c b/drivers/media/dvb/ddbridge/ddbridge-core.c
index ba9a643b9c6a..d1e91bc80e78 100644
--- a/drivers/media/dvb/ddbridge/ddbridge-core.c
+++ b/drivers/media/dvb/ddbridge/ddbridge-core.c
@@ -1480,7 +1480,7 @@ static const struct file_operations ddb_fops = {
 	.open           = ddb_open,
 };
 
-static char *ddb_devnode(struct device *device, mode_t *mode)
+static char *ddb_devnode(struct device *device, umode_t *mode)
 {
 	struct ddb *dev = dev_get_drvdata(device);
 
diff --git a/drivers/media/dvb/dvb-core/dvbdev.c b/drivers/media/dvb/dvb-core/dvbdev.c
index f73287775953..00a67326c193 100644
--- a/drivers/media/dvb/dvb-core/dvbdev.c
+++ b/drivers/media/dvb/dvb-core/dvbdev.c
@@ -450,7 +450,7 @@ static int dvb_uevent(struct device *dev, struct kobj_uevent_env *env)
 	return 0;
 }
 
-static char *dvb_devnode(struct device *dev, mode_t *mode)
+static char *dvb_devnode(struct device *dev, umode_t *mode)
 {
 	struct dvb_device *dvbdev = dev_get_drvdata(dev);
 
diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c
index 29f900065d8a..f5db8b949bc3 100644
--- a/drivers/media/rc/rc-main.c
+++ b/drivers/media/rc/rc-main.c
@@ -715,7 +715,7 @@ static void ir_close(struct input_dev *idev)
 }
 
 /* class for /sys/class/rc */
-static char *ir_devnode(struct device *dev, mode_t *mode)
+static char *ir_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "rc/%s", dev_name(dev));
 }
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 05085beb83db..3fdebd306b94 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -3267,7 +3267,7 @@ void __init console_init(void)
 	}
 }
 
-static char *tty_devnode(struct device *dev, mode_t *mode)
+static char *tty_devnode(struct device *dev, umode_t *mode)
 {
 	if (!mode)
 		return NULL;
diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index cb3a93243a05..bc5089f76cec 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -1045,7 +1045,7 @@ static const struct file_operations usblp_fops = {
 	.llseek =	noop_llseek,
 };
 
-static char *usblp_devnode(struct device *dev, mode_t *mode)
+static char *usblp_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 }
diff --git a/drivers/usb/core/file.c b/drivers/usb/core/file.c
index 99458c843d60..d95760de9e8b 100644
--- a/drivers/usb/core/file.c
+++ b/drivers/usb/core/file.c
@@ -66,7 +66,7 @@ static struct usb_class {
 	struct class *class;
 } *usb_class;
 
-static char *usb_devnode(struct device *dev, mode_t *mode)
+static char *usb_devnode(struct device *dev, umode_t *mode)
 {
 	struct usb_class_driver *drv;
 
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 73cd90012ec5..1382c90d0834 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -326,7 +326,7 @@ static const struct dev_pm_ops usb_device_pm_ops = {
 #endif	/* CONFIG_PM */
 
 
-static char *usb_devnode(struct device *dev, mode_t *mode)
+static char *usb_devnode(struct device *dev, umode_t *mode)
 {
 	struct usb_device *usb_dev;
 
diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
index 81457904d6ba..5bd4b0526de5 100644
--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -734,7 +734,7 @@ static const struct file_operations iowarrior_fops = {
 	.llseek = noop_llseek,
 };
 
-static char *iowarrior_devnode(struct device *dev, mode_t *mode)
+static char *iowarrior_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 }
diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c
index a989356f693e..94f6566b99f8 100644
--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -269,7 +269,7 @@ static const struct file_operations tower_fops = {
 	.llseek =	tower_llseek,
 };
 
-static char *legousbtower_devnode(struct device *dev, mode_t *mode)
+static char *legousbtower_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 }
diff --git a/include/linux/device.h b/include/linux/device.h
index 3136ede5a1e1..2fe0005543ed 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -294,7 +294,7 @@ struct class {
 	struct kobject			*dev_kobj;
 
 	int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
-	char *(*devnode)(struct device *dev, mode_t *mode);
+	char *(*devnode)(struct device *dev, umode_t *mode);
 
 	void (*class_release)(struct class *class);
 	void (*dev_release)(struct device *dev);
@@ -423,7 +423,7 @@ struct device_type {
 	const char *name;
 	const struct attribute_group **groups;
 	int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
-	char *(*devnode)(struct device *dev, mode_t *mode);
+	char *(*devnode)(struct device *dev, umode_t *mode);
 	void (*release)(struct device *dev);
 
 	const struct dev_pm_ops *pm;
@@ -720,7 +720,7 @@ extern int device_rename(struct device *dev, const char *new_name);
 extern int device_move(struct device *dev, struct device *new_parent,
 		       enum dpm_order dpm_order);
 extern const char *device_get_devnode(struct device *dev,
-				      mode_t *mode, const char **tmp);
+				      umode_t *mode, const char **tmp);
 extern void *dev_get_drvdata(const struct device *dev);
 extern int dev_set_drvdata(struct device *dev, void *data);
 
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 6d18f3531f18..fe23ee768589 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -163,7 +163,7 @@ struct gendisk {
                                          * disks that can't be partitioned. */
 
 	char disk_name[DISK_NAME_LEN];	/* name of major driver */
-	char *(*devnode)(struct gendisk *gd, mode_t *mode);
+	char *(*devnode)(struct gendisk *gd, umode_t *mode);
 
 	unsigned int events;		/* supported events */
 	unsigned int async_events;	/* async events, subset of all */
diff --git a/include/linux/usb.h b/include/linux/usb.h
index d3d0c1374334..a59321779f8b 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -935,7 +935,7 @@ extern struct bus_type usb_bus_type;
  */
 struct usb_class_driver {
 	char *name;
-	char *(*devnode)(struct device *dev, mode_t *mode);
+	char *(*devnode)(struct device *dev, umode_t *mode);
 	const struct file_operations *fops;
 	int minor_base;
 };
diff --git a/sound/sound_core.c b/sound/sound_core.c
index 6ce277860fd7..c6e81fb928e9 100644
--- a/sound/sound_core.c
+++ b/sound/sound_core.c
@@ -29,7 +29,7 @@ MODULE_DESCRIPTION("Core sound module");
 MODULE_AUTHOR("Alan Cox");
 MODULE_LICENSE("GPL");
 
-static char *sound_devnode(struct device *dev, mode_t *mode)
+static char *sound_devnode(struct device *dev, umode_t *mode)
 {
 	if (MAJOR(dev->devt) == SOUND_MAJOR)
 		return NULL;
-- 
cgit v1.2.3


From b10d5efdf7892d18b3b7d899edce2c8d9b80aea9 Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Tue, 17 Jan 2012 11:39:00 -0500
Subject: Documentation update for the driver model core

This patch (as1509) documents two important points regarding the use
of device structures in the driver model:

	Structures must be initialized to all 0's before they are
	passed to device_initialize().

	Structures must not be passed to device_add() or
	device_register() more than once.

Although these restrictions have applied ever since the driver model
was first created, they have not been mentioned anywhere.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/base/core.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 4a67cc0c8b37..ad29e928baaa 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -632,6 +632,11 @@ static void klist_children_put(struct klist_node *n)
  * may be used for reference counting of @dev after calling this
  * function.
  *
+ * All fields in @dev must be initialized by the caller to 0, except
+ * for those explicitly set to some other value.  The simplest
+ * approach is to use kzalloc() to allocate the structure containing
+ * @dev.
+ *
  * NOTE: Use put_device() to give up your reference instead of freeing
  * @dev directly once you have called this function.
  */
@@ -930,6 +935,13 @@ int device_private_init(struct device *dev)
  * to the global and sibling lists for the device, then
  * adds it to the other relevant subsystems of the driver model.
  *
+ * Do not call this routine or device_register() more than once for
+ * any device structure.  The driver model core is not designed to work
+ * with devices that get unregistered and then spring back to life.
+ * (Among other things, it's very hard to guarantee that all references
+ * to the previous incarnation of @dev have been dropped.)  Allocate
+ * and register a fresh new struct device instead.
+ *
  * NOTE: _Never_ directly free @dev after calling this function, even
  * if it returned an error! Always use put_device() to give up your
  * reference instead.
@@ -1090,6 +1102,9 @@ name_error:
  * have a clearly defined need to use and refcount the device
  * before it is added to the hierarchy.
  *
+ * For more information, see the kerneldoc for device_initialize()
+ * and device_add().
+ *
  * NOTE: _Never_ directly free @dev after calling this function, even
  * if it returned an error! Always use put_device() to give up the
  * reference initialized in this function instead.
-- 
cgit v1.2.3


From 268863f43629ef88763400d0cae4a66c754a0d23 Mon Sep 17 00:00:00 2001
From: majianpeng <majianpeng@gmail.com>
Date: Wed, 11 Jan 2012 15:12:06 +0000
Subject: base/core.c:fix typo in comment in function device_add

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/base/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/core.c b/drivers/base/core.c
index ad29e928baaa..74dda4f697f9 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1034,7 +1034,7 @@ int device_add(struct device *dev)
 	device_pm_add(dev);
 
 	/* Notify clients of device addition.  This call must come
-	 * after dpm_sysf_add() and before kobject_uevent().
+	 * after dpm_sysfs_add() and before kobject_uevent().
 	 */
 	if (dev->bus)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-- 
cgit v1.2.3