--- /dev/null
+/*
+ * bus.c - bus driver management
+ *
+ * Copyright (c) 2002-3 Patrick Mochel
+ * Copyright (c) 2002-3 Open Source Development Labs
+ * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2007 Novell Inc.
+ *
+ * This file is released under the GPLv2
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/mutex.h>
+#include <linux/sysfs.h>
+#include "base.h"
+#include "power/power.h"
+
+/* /sys/devices/system */
+static struct kset *system_kset;
+
+#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
+
+/*
+ * sysfs bindings for drivers
+ */
+
+#define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)
+
+
+static int __must_check bus_rescan_devices_helper(struct device *dev,
+ void *data);
+
+static struct bus_type *bus_get(struct bus_type *bus)
+{
+ if (bus) {
+ kset_get(&bus->p->subsys);
+ return bus;
+ }
+ return NULL;
+}
+
+static void bus_put(struct bus_type *bus)
+{
+ if (bus)
+ kset_put(&bus->p->subsys);
+}
+
+static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr,
+ char *buf)
+{
+ struct driver_attribute *drv_attr = to_drv_attr(attr);
+ struct driver_private *drv_priv = to_driver(kobj);
+ ssize_t ret = -EIO;
+
+ if (drv_attr->show)
+ ret = drv_attr->show(drv_priv->driver, buf);
+ return ret;
+}
+
+static ssize_t 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 driver_private *drv_priv = to_driver(kobj);
+ ssize_t ret = -EIO;
+
+ if (drv_attr->store)
+ ret = drv_attr->store(drv_priv->driver, buf, count);
+ return ret;
+}
+
+static const struct sysfs_ops driver_sysfs_ops = {
+ .show = drv_attr_show,
+ .store = drv_attr_store,
+};
+
+static void driver_release(struct kobject *kobj)
+{
+ struct driver_private *drv_priv = to_driver(kobj);
+
+ pr_debug("driver: '%s': %s\n", kobject_name(kobj), __func__);
+ kfree(drv_priv);
+}
+
+static struct kobj_type driver_ktype = {
+ .sysfs_ops = &driver_sysfs_ops,
+ .release = driver_release,
+};
+
+/*
+ * sysfs bindings for buses
+ */
+static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr,
+ char *buf)
+{
+ struct bus_attribute *bus_attr = to_bus_attr(attr);
+ struct subsys_private *subsys_priv = to_subsys_private(kobj);
+ ssize_t ret = 0;
+
+ if (bus_attr->show)
+ ret = bus_attr->show(subsys_priv->bus, buf);
+ return ret;
+}
+
+static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t count)
+{
+ struct bus_attribute *bus_attr = to_bus_attr(attr);
+ struct subsys_private *subsys_priv = to_subsys_private(kobj);
+ ssize_t ret = 0;
+
+ if (bus_attr->store)
+ ret = bus_attr->store(subsys_priv->bus, buf, count);
+ return ret;
+}
+
+static const struct sysfs_ops bus_sysfs_ops = {
+ .show = bus_attr_show,
+ .store = bus_attr_store,
+};
+
+int bus_create_file(struct bus_type *bus, struct bus_attribute *attr)
+{
+ int error;
+ if (bus_get(bus)) {
+ error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);
+ bus_put(bus);
+ } else
+ error = -EINVAL;
+ return error;
+}
+EXPORT_SYMBOL_GPL(bus_create_file);
+
+void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr)
+{
+ if (bus_get(bus)) {
+ sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);
+ bus_put(bus);
+ }
+}
+EXPORT_SYMBOL_GPL(bus_remove_file);
+
+static void bus_release(struct kobject *kobj)
+{
+ struct subsys_private *priv =
+ container_of(kobj, typeof(*priv), subsys.kobj);
+ struct bus_type *bus = priv->bus;
+
+ kfree(priv);
+ bus->p = NULL;
+}
+
+static struct kobj_type bus_ktype = {
+ .sysfs_ops = &bus_sysfs_ops,
+ .release = bus_release,
+};
+
+static int bus_uevent_filter(struct kset *kset, struct kobject *kobj)
+{
+ struct kobj_type *ktype = get_ktype(kobj);
+
+ if (ktype == &bus_ktype)
+ return 1;
+ return 0;
+}
+
+static const struct kset_uevent_ops bus_uevent_ops = {
+ .filter = bus_uevent_filter,
+};
+
+static struct kset *bus_kset;
+
+/* Manually detach a device from its associated driver. */
+static ssize_t unbind_store(struct device_driver *drv, const char *buf,
+ size_t count)
+{
+ struct bus_type *bus = bus_get(drv->bus);
+ struct device *dev;
+ int err = -ENODEV;
+
+ dev = bus_find_device_by_name(bus, NULL, buf);
+ if (dev && dev->driver == drv) {
+ if (dev->parent) /* Needed for USB */
+ device_lock(dev->parent);
+ device_release_driver(dev);
+ if (dev->parent)
+ device_unlock(dev->parent);
+ err = count;
+ }
+ put_device(dev);
+ bus_put(bus);
+ return err;
+}
+static DRIVER_ATTR_WO(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 bind_store(struct device_driver *drv, const char *buf,
+ size_t count)
+{
+ struct bus_type *bus = bus_get(drv->bus);
+ struct device *dev;
+ int err = -ENODEV;
+
+ dev = bus_find_device_by_name(bus, NULL, buf);
+ if (dev && dev->driver == NULL && driver_match_device(drv, dev)) {
+ if (dev->parent) /* Needed for USB */
+ device_lock(dev->parent);
+ device_lock(dev);
+ err = driver_probe_device(drv, dev);
+ device_unlock(dev);
+ if (dev->parent)
+ device_unlock(dev->parent);
+
+ if (err > 0) {
+ /* success */
+ err = count;
+ } else if (err == 0) {
+ /* driver didn't accept device */
+ err = -ENODEV;
+ }
+ }
+ put_device(dev);
+ bus_put(bus);
+ return err;
+}
+static DRIVER_ATTR_WO(bind);
+
+static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
+{
+ return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
+}
+
+static ssize_t store_drivers_autoprobe(struct bus_type *bus,
+ const char *buf, size_t count)
+{
+ if (buf[0] == '0')
+ bus->p->drivers_autoprobe = 0;
+ else
+ bus->p->drivers_autoprobe = 1;
+ return count;
+}
+
+static ssize_t store_drivers_probe(struct bus_type *bus,
+ const char *buf, size_t count)
+{
+ struct device *dev;
+ int err = -EINVAL;
+
+ dev = bus_find_device_by_name(bus, NULL, buf);
+ if (!dev)
+ return -ENODEV;
+ if (bus_rescan_devices_helper(dev, NULL) == 0)
+ err = count;
+ put_device(dev);
+ return err;
+}
+
+static struct device *next_device(struct klist_iter *i)
+{
+ struct klist_node *n = klist_next(i);
+ struct device *dev = NULL;
+ struct device_private *dev_prv;
+
+ if (n) {
+ dev_prv = to_device_private_bus(n);
+ dev = dev_prv->device;
+ }
+ return dev;
+}
+
+/**
+ * bus_for_each_dev - device iterator.
+ * @bus: bus type.
+ * @start: device to start iterating from.
+ * @data: data for the callback.
+ * @fn: function to be called for each device.
+ *
+ * Iterate over @bus's list of devices, and call @fn for each,
+ * passing it @data. If @start is not NULL, we use that device to
+ * begin iterating from.
+ *
+ * We check the return of @fn each time. If it returns anything
+ * other than 0, we break out and return that value.
+ *
+ * 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 so, and increment the reference
+ * count in the supplied callback.
+ */
+int bus_for_each_dev(struct bus_type *bus, struct device *start,
+ void *data, int (*fn)(struct device *, void *))
+{
+ struct klist_iter i;
+ struct device *dev;
+ int error = 0;
+
+ if (!bus || !bus->p)
+ return -EINVAL;
+
+ klist_iter_init_node(&bus->p->klist_devices, &i,
+ (start ? &start->p->knode_bus : NULL));
+ while ((dev = next_device(&i)) && !error)
+ error = fn(dev, data);
+ klist_iter_exit(&i);
+ return error;
+}
+EXPORT_SYMBOL_GPL(bus_for_each_dev);
+
+/**
+ * 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 *dev, void *data))
+{
+ struct klist_iter i;
+ struct device *dev;
+
+ if (!bus || !bus->p)
+ return NULL;
+
+ klist_iter_init_node(&bus->p->klist_devices, &i,
+ (start ? &start->p->knode_bus : NULL));
+ while ((dev = next_device(&i)))
+ if (match(dev, data) && get_device(dev))
+ break;
+ klist_iter_exit(&i);
+ return dev;
+}
+EXPORT_SYMBOL_GPL(bus_find_device);
+
+static int match_name(struct device *dev, void *data)
+{
+ const char *name = data;
+
+ return sysfs_streq(name, dev_name(dev));
+}
+
+/**
+ * bus_find_device_by_name - device iterator for locating a particular device of a specific name
+ * @bus: bus type
+ * @start: Device to begin with
+ * @name: name of the device to match
+ *
+ * This is similar to the bus_find_device() function above, but it handles
+ * searching by a name automatically, no need to write another strcmp matching
+ * function.
+ */
+struct device *bus_find_device_by_name(struct bus_type *bus,
+ struct device *start, const char *name)
+{
+ return bus_find_device(bus, start, (void *)name, match_name);
+}
+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);
+ struct driver_private *drv_priv;
+
+ if (n) {
+ drv_priv = container_of(n, struct driver_private, knode_bus);
+ return drv_priv->driver;
+ }
+ return NULL;
+}
+
+/**
+ * bus_for_each_drv - driver iterator
+ * @bus: bus we're dealing with.
+ * @start: driver to start iterating on.
+ * @data: data to pass to the callback.
+ * @fn: function to call for each driver.
+ *
+ * This is nearly identical to the device iterator above.
+ * We iterate over each driver that belongs to @bus, and call
+ * @fn for each. If @fn returns anything but 0, we break out
+ * 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
+ * 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
+ * so it doesn't disappear before returning to the caller.
+ */
+int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
+ void *data, int (*fn)(struct device_driver *, void *))
+{
+ struct klist_iter i;
+ struct device_driver *drv;
+ int error = 0;
+
+ if (!bus)
+ return -EINVAL;
+
+ klist_iter_init_node(&bus->p->klist_drivers, &i,
+ start ? &start->p->knode_bus : NULL);
+ while ((drv = next_driver(&i)) && !error)
+ error = fn(drv, data);
+ klist_iter_exit(&i);
+ return error;
+}
+EXPORT_SYMBOL_GPL(bus_for_each_drv);
+
+static int device_add_attrs(struct bus_type *bus, struct device *dev)
+{
+ int error = 0;
+ int i;
+
+ if (!bus->dev_attrs)
+ return 0;
+
+ for (i = 0; bus->dev_attrs[i].attr.name; i++) {
+ error = device_create_file(dev, &bus->dev_attrs[i]);
+ if (error) {
+ while (--i >= 0)
+ device_remove_file(dev, &bus->dev_attrs[i]);
+ break;
+ }
+ }
+ return error;
+}
+
+static void device_remove_attrs(struct bus_type *bus, struct device *dev)
+{
+ int i;
+
+ if (bus->dev_attrs) {
+ for (i = 0; bus->dev_attrs[i].attr.name; i++)
+ device_remove_file(dev, &bus->dev_attrs[i]);
+ }
+}
+
+/**
+ * bus_add_device - add device to bus
+ * @dev: device being added
+ *
+ * - Add device's bus attributes.
+ * - Create links to device's bus.
+ * - Add the device to its bus's list of devices.
+ */
+int bus_add_device(struct device *dev)
+{
+ struct bus_type *bus = bus_get(dev->bus);
+ int error = 0;
+
+ if (bus) {
+ pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));
+ error = device_add_attrs(bus, dev);
+ if (error)
+ goto out_put;
+ error = device_add_groups(dev, bus->dev_groups);
+ if (error)
+ goto out_id;
+ error = sysfs_create_link(&bus->p->devices_kset->kobj,
+ &dev->kobj, dev_name(dev));
+ if (error)
+ goto out_groups;
+ error = sysfs_create_link(&dev->kobj,
+ &dev->bus->p->subsys.kobj, "subsystem");
+ if (error)
+ goto out_subsys;
+ klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
+ }
+ return 0;
+
+out_subsys:
+ sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
+out_groups:
+ device_remove_groups(dev, bus->dev_groups);
+out_id:
+ device_remove_attrs(bus, dev);
+out_put:
+ bus_put(dev->bus);
+ return error;
+}
+
+/**
+ * bus_probe_device - probe drivers for a new device
+ * @dev: device to probe
+ *
+ * - Automatically probe for a driver if the bus allows it.
+ */
+void bus_probe_device(struct device *dev)
+{
+ struct bus_type *bus = dev->bus;
+ struct subsys_interface *sif;
+ int ret;
+
+ 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 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)
+{
+ 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);
+ device_remove_groups(dev, dev->bus->dev_groups);
+ 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 __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);
+}
+
+static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe);
+static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO,
+ show_drivers_autoprobe, store_drivers_autoprobe);
+
+static int add_probe_files(struct bus_type *bus)
+{
+ int retval;
+
+ retval = bus_create_file(bus, &bus_attr_drivers_probe);
+ if (retval)
+ goto out;
+
+ retval = bus_create_file(bus, &bus_attr_drivers_autoprobe);
+ if (retval)
+ bus_remove_file(bus, &bus_attr_drivers_probe);
+out:
+ return retval;
+}
+
+static void remove_probe_files(struct bus_type *bus)
+{
+ bus_remove_file(bus, &bus_attr_drivers_autoprobe);
+ bus_remove_file(bus, &bus_attr_drivers_probe);
+}
+
+static ssize_t uevent_store(struct device_driver *drv, const char *buf,
+ size_t count)
+{
+ enum kobject_action action;
+
+ if (kobject_action_type(buf, count, &action) == 0)
+ kobject_uevent(&drv->p->kobj, action);
+ return count;
+}
+static DRIVER_ATTR_WO(uevent);
+
+/**
+ * bus_add_driver - Add a driver to the bus.
+ * @drv: driver.
+ */
+int bus_add_driver(struct device_driver *drv)
+{
+ struct bus_type *bus;
+ struct driver_private *priv;
+ int error = 0;
+
+ bus = bus_get(drv->bus);
+ if (!bus)
+ return -EINVAL;
+
+ pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name);
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv) {
+ error = -ENOMEM;
+ goto out_put_bus;
+ }
+ klist_init(&priv->klist_devices, NULL, NULL);
+ priv->driver = drv;
+ drv->p = priv;
+ priv->kobj.kset = bus->p->drivers_kset;
+ error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL,
+ "%s", drv->name);
+ if (error)
+ goto out_unregister;
+
+ klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
+ if (drv->bus->p->drivers_autoprobe) {
+ error = driver_attach(drv);
+ if (error)
+ goto out_unregister;
+ }
+ module_add_driver(drv->owner, drv);
+
+ error = driver_create_file(drv, &driver_attr_uevent);
+ if (error) {
+ printk(KERN_ERR "%s: uevent attr (%s) failed\n",
+ __func__, drv->name);
+ }
+ error = driver_add_groups(drv, bus->drv_groups);
+ if (error) {
+ /* How the hell do we get out of this pickle? Give up */
+ printk(KERN_ERR "%s: driver_create_groups(%s) failed\n",
+ __func__, drv->name);
+ }
+
+ if (!drv->suppress_bind_attrs) {
+ error = add_bind_files(drv);
+ if (error) {
+ /* Ditto */
+ printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
+ __func__, drv->name);
+ }
+ }
+
+ return 0;
+
+out_unregister:
+ kobject_put(&priv->kobj);
+ kfree(drv->p);
+ drv->p = NULL;
+out_put_bus:
+ bus_put(bus);
+ return error;
+}
+
+/**
+ * bus_remove_driver - delete driver from bus's knowledge.
+ * @drv: driver.
+ *
+ * Detach the driver from the devices it controls, and remove
+ * it from its bus's list of drivers. Finally, we drop the reference
+ * to the bus we took in bus_add_driver().
+ */
+void bus_remove_driver(struct device_driver *drv)
+{
+ if (!drv->bus)
+ return;
+
+ if (!drv->suppress_bind_attrs)
+ remove_bind_files(drv);
+ driver_remove_groups(drv, drv->bus->drv_groups);
+ driver_remove_file(drv, &driver_attr_uevent);
+ klist_remove(&drv->p->knode_bus);
+ pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name);
+ driver_detach(drv);
+ module_remove_driver(drv);
+ kobject_put(&drv->p->kobj);
+ bus_put(drv->bus);
+}
+
+/* Helper for bus_rescan_devices's iter */
+static int __must_check bus_rescan_devices_helper(struct device *dev,
+ void *data)
+{
+ int ret = 0;
+
+ if (!dev->driver) {
+ if (dev->parent) /* Needed for USB */
+ device_lock(dev->parent);
+ ret = device_attach(dev);
+ if (dev->parent)
+ device_unlock(dev->parent);
+ }
+ return ret < 0 ? ret : 0;
+}
+
+/**
+ * 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 by calling device_attach() for the unbound devices.
+ */
+int bus_rescan_devices(struct bus_type *bus)
+{
+ return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
+}
+EXPORT_SYMBOL_GPL(bus_rescan_devices);
+
+/**
+ * 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 */
+ device_lock(dev->parent);
+ device_release_driver(dev);
+ if (dev->parent)
+ device_unlock(dev->parent);
+ }
+ return bus_rescan_devices_helper(dev, NULL);
+}
+EXPORT_SYMBOL_GPL(device_reprobe);
+
+/**
+ * find_bus - locate bus by name.
+ * @name: name of 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_kset, name);
+ return k ? to_bus(k) : NULL;
+}
+#endif /* 0 */
+
+static int bus_add_groups(struct bus_type *bus,
+ const struct attribute_group **groups)
+{
+ return sysfs_create_groups(&bus->p->subsys.kobj, groups);
+}
+
+static void bus_remove_groups(struct bus_type *bus,
+ const struct attribute_group **groups)
+{
+ sysfs_remove_groups(&bus->p->subsys.kobj, groups);
+}
+
+static void klist_devices_get(struct klist_node *n)
+{
+ struct device_private *dev_prv = to_device_private_bus(n);
+ struct device *dev = dev_prv->device;
+
+ get_device(dev);
+}
+
+static void klist_devices_put(struct klist_node *n)
+{
+ struct device_private *dev_prv = to_device_private_bus(n);
+ struct device *dev = dev_prv->device;
+
+ put_device(dev);
+}
+
+static ssize_t bus_uevent_store(struct bus_type *bus,
+ const char *buf, size_t count)
+{
+ enum kobject_action action;
+
+ if (kobject_action_type(buf, count, &action) == 0)
+ kobject_uevent(&bus->p->subsys.kobj, action);
+ return count;
+}
+static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
+
+/**
+ * bus_register - register a driver-core subsystem
+ * @bus: bus to register
+ *
+ * Once we have that, we register the bus with the kobject
+ * infrastructure, then register the children subsystems it has:
+ * the devices and drivers that belong to the subsystem.
+ */
+int bus_register(struct bus_type *bus)
+{
+ int retval;
+ struct subsys_private *priv;
+ struct lock_class_key *key = &bus->lock_key;
+
+ priv = kzalloc(sizeof(struct subsys_private), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->bus = bus;
+ bus->p = priv;
+
+ BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier);
+
+ retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);
+ if (retval)
+ goto out;
+
+ priv->subsys.kobj.kset = bus_kset;
+ priv->subsys.kobj.ktype = &bus_ktype;
+ priv->drivers_autoprobe = 1;
+
+ retval = kset_register(&priv->subsys);
+ if (retval)
+ goto out;
+
+ retval = bus_create_file(bus, &bus_attr_uevent);
+ if (retval)
+ goto bus_uevent_fail;
+
+ priv->devices_kset = kset_create_and_add("devices", NULL,
+ &priv->subsys.kobj);
+ if (!priv->devices_kset) {
+ retval = -ENOMEM;
+ goto bus_devices_fail;
+ }
+
+ priv->drivers_kset = kset_create_and_add("drivers", NULL,
+ &priv->subsys.kobj);
+ if (!priv->drivers_kset) {
+ retval = -ENOMEM;
+ 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);
+
+ retval = add_probe_files(bus);
+ if (retval)
+ goto bus_probe_files_fail;
+
+ retval = bus_add_groups(bus, bus->bus_groups);
+ if (retval)
+ goto bus_groups_fail;
+
+ pr_debug("bus: '%s': registered\n", bus->name);
+ return 0;
+
+bus_groups_fail:
+ remove_probe_files(bus);
+bus_probe_files_fail:
+ kset_unregister(bus->p->drivers_kset);
+bus_drivers_fail:
+ kset_unregister(bus->p->devices_kset);
+bus_devices_fail:
+ bus_remove_file(bus, &bus_attr_uevent);
+bus_uevent_fail:
+ kset_unregister(&bus->p->subsys);
+out:
+ kfree(bus->p);
+ bus->p = NULL;
+ return retval;
+}
+EXPORT_SYMBOL_GPL(bus_register);
+
+/**
+ * bus_unregister - remove a bus from the system
+ * @bus: bus.
+ *
+ * Unregister the child subsystems and the bus itself.
+ * Finally, we call bus_put() to release the refcount
+ */
+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_groups(bus, bus->bus_groups);
+ remove_probe_files(bus);
+ kset_unregister(bus->p->drivers_kset);
+ kset_unregister(bus->p->devices_kset);
+ bus_remove_file(bus, &bus_attr_uevent);
+ kset_unregister(&bus->p->subsys);
+}
+EXPORT_SYMBOL_GPL(bus_unregister);
+
+int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&bus->p->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->p->bus_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(bus_unregister_notifier);
+
+struct kset *bus_get_kset(struct bus_type *bus)
+{
+ return &bus->p->subsys;
+}
+EXPORT_SYMBOL_GPL(bus_get_kset);
+
+struct klist *bus_get_device_klist(struct bus_type *bus)
+{
+ return &bus->p->klist_devices;
+}
+EXPORT_SYMBOL_GPL(bus_get_device_klist);
+
+/*
+ * Yes, this forcibly breaks the klist abstraction temporarily. It
+ * just wants to sort the klist, not change reference counts and
+ * take/drop locks rapidly in the process. It does all this while
+ * holding the lock for the list, so objects can't otherwise be
+ * added/removed while we're swizzling.
+ */
+static void device_insertion_sort_klist(struct device *a, struct list_head *list,
+ int (*compare)(const struct device *a,
+ const struct device *b))
+{
+ struct list_head *pos;
+ struct klist_node *n;
+ struct device_private *dev_prv;
+ struct device *b;
+
+ list_for_each(pos, list) {
+ n = container_of(pos, struct klist_node, n_node);
+ dev_prv = to_device_private_bus(n);
+ b = dev_prv->device;
+ if (compare(a, b) <= 0) {
+ list_move_tail(&a->p->knode_bus.n_node,
+ &b->p->knode_bus.n_node);
+ return;
+ }
+ }
+ list_move_tail(&a->p->knode_bus.n_node, list);
+}
+
+void bus_sort_breadthfirst(struct bus_type *bus,
+ int (*compare)(const struct device *a,
+ const struct device *b))
+{
+ LIST_HEAD(sorted_devices);
+ struct list_head *pos, *tmp;
+ struct klist_node *n;
+ struct device_private *dev_prv;
+ struct device *dev;
+ struct klist *device_klist;
+
+ device_klist = bus_get_device_klist(bus);
+
+ spin_lock(&device_klist->k_lock);
+ list_for_each_safe(pos, tmp, &device_klist->k_list) {
+ n = container_of(pos, struct klist_node, n_node);
+ dev_prv = to_device_private_bus(n);
+ dev = dev_prv->device;
+ device_insertion_sort_klist(dev, &sorted_devices, compare);
+ }
+ list_splice(&sorted_devices, &device_klist->k_list);
+ spin_unlock(&device_klist->k_lock);
+}
+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;
+ struct subsys_dev_iter iter;
+ struct device *dev;
+
+ if (!sif || !sif->subsys)
+ return;
+
+ subsys = sif->subsys;
+
+ 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);
+}
+
+static int subsys_register(struct bus_type *subsys,
+ const struct attribute_group **groups,
+ struct kobject *parent_of_root)
+{
+ 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 = parent_of_root;
+ 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;
+}
+
+/**
+ * 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 explicitly 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)
+{
+ return subsys_register(subsys, groups, &system_kset->kobj);
+}
+EXPORT_SYMBOL_GPL(subsys_system_register);
+
+/**
+ * subsys_virtual_register - register a subsystem at /sys/devices/virtual/
+ * @subsys: virtual subsystem
+ * @groups: default attributes for the root device
+ *
+ * All 'virtual' subsystems have a /sys/devices/system/<name> root device
+ * with the name of the subystem. The root device can carry subsystem-wide
+ * attributes. All registered devices are below this single root device.
+ * There's no restriction on device naming. This is for kernel software
+ * constructs which need sysfs interface.
+ */
+int subsys_virtual_register(struct bus_type *subsys,
+ const struct attribute_group **groups)
+{
+ struct kobject *virtual_dir;
+
+ virtual_dir = virtual_device_parent(NULL);
+ if (!virtual_dir)
+ return -ENOMEM;
+
+ return subsys_register(subsys, groups, virtual_dir);
+}
+EXPORT_SYMBOL_GPL(subsys_virtual_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;
+}
Code Review / kvmfornfv.git / blobdiff