![Phil Carmody](/assets/img/avatar_default.png)
priv is drv->p. So only free drv->p after we've finished using priv. Found using a static code analysis tool Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
1060 lines
26 KiB
C
1060 lines
26 KiB
C
/*
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* bus.c - bus driver management
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*
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* Copyright (c) 2002-3 Patrick Mochel
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* Copyright (c) 2002-3 Open Source Development Labs
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* Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
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* Copyright (c) 2007 Novell Inc.
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*
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* This file is released under the GPLv2
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*
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*/
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/string.h>
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#include "base.h"
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#include "power/power.h"
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#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
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#define to_bus(obj) container_of(obj, struct bus_type_private, subsys.kobj)
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/*
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* sysfs bindings for drivers
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*/
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#define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)
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static int __must_check bus_rescan_devices_helper(struct device *dev,
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void *data);
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static struct bus_type *bus_get(struct bus_type *bus)
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{
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if (bus) {
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kset_get(&bus->p->subsys);
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return bus;
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}
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return NULL;
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}
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static void bus_put(struct bus_type *bus)
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{
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if (bus)
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kset_put(&bus->p->subsys);
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}
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static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr,
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char *buf)
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{
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struct driver_attribute *drv_attr = to_drv_attr(attr);
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struct driver_private *drv_priv = to_driver(kobj);
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ssize_t ret = -EIO;
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if (drv_attr->show)
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ret = drv_attr->show(drv_priv->driver, buf);
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return ret;
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}
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static ssize_t drv_attr_store(struct kobject *kobj, struct attribute *attr,
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const char *buf, size_t count)
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{
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struct driver_attribute *drv_attr = to_drv_attr(attr);
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struct driver_private *drv_priv = to_driver(kobj);
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ssize_t ret = -EIO;
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if (drv_attr->store)
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ret = drv_attr->store(drv_priv->driver, buf, count);
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return ret;
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}
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static struct sysfs_ops driver_sysfs_ops = {
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.show = drv_attr_show,
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.store = drv_attr_store,
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};
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static void driver_release(struct kobject *kobj)
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{
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struct driver_private *drv_priv = to_driver(kobj);
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pr_debug("driver: '%s': %s\n", kobject_name(kobj), __func__);
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kfree(drv_priv);
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}
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static struct kobj_type driver_ktype = {
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.sysfs_ops = &driver_sysfs_ops,
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.release = driver_release,
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};
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/*
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* sysfs bindings for buses
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*/
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static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr,
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char *buf)
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{
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struct bus_attribute *bus_attr = to_bus_attr(attr);
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struct bus_type_private *bus_priv = to_bus(kobj);
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ssize_t ret = 0;
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if (bus_attr->show)
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ret = bus_attr->show(bus_priv->bus, buf);
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return ret;
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}
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static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr,
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const char *buf, size_t count)
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{
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struct bus_attribute *bus_attr = to_bus_attr(attr);
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struct bus_type_private *bus_priv = to_bus(kobj);
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ssize_t ret = 0;
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if (bus_attr->store)
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ret = bus_attr->store(bus_priv->bus, buf, count);
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return ret;
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}
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static struct sysfs_ops bus_sysfs_ops = {
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.show = bus_attr_show,
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.store = bus_attr_store,
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};
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int bus_create_file(struct bus_type *bus, struct bus_attribute *attr)
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{
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int error;
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if (bus_get(bus)) {
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error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);
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bus_put(bus);
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} else
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error = -EINVAL;
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return error;
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}
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EXPORT_SYMBOL_GPL(bus_create_file);
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void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr)
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{
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if (bus_get(bus)) {
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sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);
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bus_put(bus);
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}
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}
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EXPORT_SYMBOL_GPL(bus_remove_file);
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static struct kobj_type bus_ktype = {
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.sysfs_ops = &bus_sysfs_ops,
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};
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static int bus_uevent_filter(struct kset *kset, struct kobject *kobj)
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{
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struct kobj_type *ktype = get_ktype(kobj);
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if (ktype == &bus_ktype)
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return 1;
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return 0;
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}
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static struct kset_uevent_ops bus_uevent_ops = {
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.filter = bus_uevent_filter,
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};
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static struct kset *bus_kset;
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#ifdef CONFIG_HOTPLUG
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/* Manually detach a device from its associated driver. */
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static ssize_t driver_unbind(struct device_driver *drv,
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const char *buf, size_t count)
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{
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struct bus_type *bus = bus_get(drv->bus);
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struct device *dev;
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int err = -ENODEV;
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dev = bus_find_device_by_name(bus, NULL, buf);
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if (dev && dev->driver == drv) {
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if (dev->parent) /* Needed for USB */
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down(&dev->parent->sem);
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device_release_driver(dev);
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if (dev->parent)
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up(&dev->parent->sem);
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err = count;
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}
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put_device(dev);
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bus_put(bus);
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return err;
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}
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static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind);
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/*
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* Manually attach a device to a driver.
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* Note: the driver must want to bind to the device,
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* it is not possible to override the driver's id table.
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*/
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static ssize_t driver_bind(struct device_driver *drv,
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const char *buf, size_t count)
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{
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struct bus_type *bus = bus_get(drv->bus);
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struct device *dev;
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int err = -ENODEV;
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dev = bus_find_device_by_name(bus, NULL, buf);
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if (dev && dev->driver == NULL && driver_match_device(drv, dev)) {
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if (dev->parent) /* Needed for USB */
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down(&dev->parent->sem);
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down(&dev->sem);
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err = driver_probe_device(drv, dev);
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up(&dev->sem);
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if (dev->parent)
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up(&dev->parent->sem);
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if (err > 0) {
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/* success */
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err = count;
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} else if (err == 0) {
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/* driver didn't accept device */
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err = -ENODEV;
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}
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}
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put_device(dev);
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bus_put(bus);
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return err;
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}
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static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind);
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static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
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{
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return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
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}
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static ssize_t store_drivers_autoprobe(struct bus_type *bus,
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const char *buf, size_t count)
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{
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if (buf[0] == '0')
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bus->p->drivers_autoprobe = 0;
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else
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bus->p->drivers_autoprobe = 1;
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return count;
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}
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static ssize_t store_drivers_probe(struct bus_type *bus,
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const char *buf, size_t count)
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{
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struct device *dev;
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dev = bus_find_device_by_name(bus, NULL, buf);
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if (!dev)
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return -ENODEV;
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if (bus_rescan_devices_helper(dev, NULL) != 0)
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return -EINVAL;
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return count;
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}
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#endif
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static struct device *next_device(struct klist_iter *i)
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{
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struct klist_node *n = klist_next(i);
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struct device *dev = NULL;
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struct device_private *dev_prv;
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if (n) {
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dev_prv = to_device_private_bus(n);
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dev = dev_prv->device;
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}
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return dev;
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}
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/**
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* bus_for_each_dev - device iterator.
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* @bus: bus type.
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* @start: device to start iterating from.
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* @data: data for the callback.
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* @fn: function to be called for each device.
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*
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* Iterate over @bus's list of devices, and call @fn for each,
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* passing it @data. If @start is not NULL, we use that device to
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* begin iterating from.
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*
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* We check the return of @fn each time. If it returns anything
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* other than 0, we break out and return that value.
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*
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* NOTE: The device that returns a non-zero value is not retained
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* in any way, nor is its refcount incremented. If the caller needs
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* to retain this data, it should do so, and increment the reference
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* count in the supplied callback.
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*/
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int bus_for_each_dev(struct bus_type *bus, struct device *start,
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void *data, int (*fn)(struct device *, void *))
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{
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struct klist_iter i;
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struct device *dev;
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int error = 0;
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if (!bus)
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return -EINVAL;
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klist_iter_init_node(&bus->p->klist_devices, &i,
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(start ? &start->p->knode_bus : NULL));
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while ((dev = next_device(&i)) && !error)
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error = fn(dev, data);
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klist_iter_exit(&i);
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return error;
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}
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EXPORT_SYMBOL_GPL(bus_for_each_dev);
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/**
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* bus_find_device - device iterator for locating a particular device.
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* @bus: bus type
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* @start: Device to begin with
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* @data: Data to pass to match function
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* @match: Callback function to check device
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*
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* This is similar to the bus_for_each_dev() function above, but it
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* returns a reference to a device that is 'found' for later use, as
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* determined by the @match callback.
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*
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* The callback should return 0 if the device doesn't match and non-zero
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* if it does. If the callback returns non-zero, this function will
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* return to the caller and not iterate over any more devices.
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*/
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struct device *bus_find_device(struct bus_type *bus,
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struct device *start, void *data,
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int (*match)(struct device *dev, void *data))
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{
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struct klist_iter i;
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struct device *dev;
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if (!bus)
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return NULL;
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klist_iter_init_node(&bus->p->klist_devices, &i,
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(start ? &start->p->knode_bus : NULL));
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while ((dev = next_device(&i)))
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if (match(dev, data) && get_device(dev))
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break;
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klist_iter_exit(&i);
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return dev;
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}
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EXPORT_SYMBOL_GPL(bus_find_device);
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static int match_name(struct device *dev, void *data)
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{
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const char *name = data;
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return sysfs_streq(name, dev_name(dev));
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}
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/**
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* bus_find_device_by_name - device iterator for locating a particular device of a specific name
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* @bus: bus type
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* @start: Device to begin with
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* @name: name of the device to match
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*
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* This is similar to the bus_find_device() function above, but it handles
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* searching by a name automatically, no need to write another strcmp matching
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* function.
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*/
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struct device *bus_find_device_by_name(struct bus_type *bus,
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struct device *start, const char *name)
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{
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return bus_find_device(bus, start, (void *)name, match_name);
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}
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EXPORT_SYMBOL_GPL(bus_find_device_by_name);
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static struct device_driver *next_driver(struct klist_iter *i)
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{
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struct klist_node *n = klist_next(i);
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struct driver_private *drv_priv;
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if (n) {
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drv_priv = container_of(n, struct driver_private, knode_bus);
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return drv_priv->driver;
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}
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return NULL;
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}
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/**
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* bus_for_each_drv - driver iterator
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* @bus: bus we're dealing with.
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* @start: driver to start iterating on.
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* @data: data to pass to the callback.
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* @fn: function to call for each driver.
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*
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* This is nearly identical to the device iterator above.
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* We iterate over each driver that belongs to @bus, and call
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* @fn for each. If @fn returns anything but 0, we break out
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* and return it. If @start is not NULL, we use it as the head
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* of the list.
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*
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* NOTE: we don't return the driver that returns a non-zero
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* value, nor do we leave the reference count incremented for that
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* driver. If the caller needs to know that info, it must set it
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* in the callback. It must also be sure to increment the refcount
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* so it doesn't disappear before returning to the caller.
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*/
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int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
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void *data, int (*fn)(struct device_driver *, void *))
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{
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struct klist_iter i;
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struct device_driver *drv;
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int error = 0;
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if (!bus)
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return -EINVAL;
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klist_iter_init_node(&bus->p->klist_drivers, &i,
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start ? &start->p->knode_bus : NULL);
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while ((drv = next_driver(&i)) && !error)
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error = fn(drv, data);
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klist_iter_exit(&i);
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return error;
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}
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EXPORT_SYMBOL_GPL(bus_for_each_drv);
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static int device_add_attrs(struct bus_type *bus, struct device *dev)
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{
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int error = 0;
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int i;
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if (!bus->dev_attrs)
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return 0;
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for (i = 0; attr_name(bus->dev_attrs[i]); i++) {
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error = device_create_file(dev, &bus->dev_attrs[i]);
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if (error) {
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while (--i >= 0)
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device_remove_file(dev, &bus->dev_attrs[i]);
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break;
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}
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}
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return error;
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}
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|
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static void device_remove_attrs(struct bus_type *bus, struct device *dev)
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{
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int i;
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if (bus->dev_attrs) {
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for (i = 0; attr_name(bus->dev_attrs[i]); i++)
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device_remove_file(dev, &bus->dev_attrs[i]);
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}
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}
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|
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#ifdef CONFIG_SYSFS_DEPRECATED
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static int make_deprecated_bus_links(struct device *dev)
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{
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return sysfs_create_link(&dev->kobj,
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&dev->bus->p->subsys.kobj, "bus");
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}
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static void remove_deprecated_bus_links(struct device *dev)
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{
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sysfs_remove_link(&dev->kobj, "bus");
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}
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#else
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static inline int make_deprecated_bus_links(struct device *dev) { return 0; }
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static inline void remove_deprecated_bus_links(struct device *dev) { }
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#endif
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|
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/**
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* bus_add_device - add device to bus
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* @dev: device being added
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*
|
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* - Add device's bus attributes.
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* - Create links to device's bus.
|
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* - Add the device to its bus's list of devices.
|
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*/
|
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int bus_add_device(struct device *dev)
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{
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struct bus_type *bus = bus_get(dev->bus);
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int error = 0;
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|
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if (bus) {
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pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));
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error = device_add_attrs(bus, dev);
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if (error)
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goto out_put;
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error = sysfs_create_link(&bus->p->devices_kset->kobj,
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&dev->kobj, dev_name(dev));
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if (error)
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goto out_id;
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error = sysfs_create_link(&dev->kobj,
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&dev->bus->p->subsys.kobj, "subsystem");
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if (error)
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goto out_subsys;
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error = make_deprecated_bus_links(dev);
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if (error)
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goto out_deprecated;
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klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
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}
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return 0;
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|
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out_deprecated:
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sysfs_remove_link(&dev->kobj, "subsystem");
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out_subsys:
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sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
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out_id:
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device_remove_attrs(bus, dev);
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out_put:
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bus_put(dev->bus);
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return error;
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}
|
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|
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/**
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* bus_probe_device - probe drivers for a new device
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* @dev: device to probe
|
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*
|
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* - Automatically probe for a driver if the bus allows it.
|
|
*/
|
|
void bus_probe_device(struct device *dev)
|
|
{
|
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struct bus_type *bus = dev->bus;
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int ret;
|
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|
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if (bus && bus->p->drivers_autoprobe) {
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ret = device_attach(dev);
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WARN_ON(ret < 0);
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}
|
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}
|
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|
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/**
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|
* bus_remove_device - remove device from bus
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|
* @dev: device to be removed
|
|
*
|
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* - Remove symlink from bus's directory.
|
|
* - Delete device from bus's list.
|
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* - 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");
|
|
remove_deprecated_bus_links(dev);
|
|
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)
|
|
{
|
|
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);
|
|
}
|
|
|
|
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);
|
|
}
|
|
#else
|
|
static inline int add_bind_files(struct device_driver *drv) { return 0; }
|
|
static inline void remove_bind_files(struct device_driver *drv) {}
|
|
static inline int add_probe_files(struct bus_type *bus) { return 0; }
|
|
static inline void remove_probe_files(struct bus_type *bus) {}
|
|
#endif
|
|
|
|
static ssize_t driver_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(uevent, S_IWUSR, NULL, driver_uevent_store);
|
|
|
|
/**
|
|
* 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;
|
|
|
|
if (drv->bus->p->drivers_autoprobe) {
|
|
error = driver_attach(drv);
|
|
if (error)
|
|
goto out_unregister;
|
|
}
|
|
klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
|
|
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_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",
|
|
__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);
|
|
}
|
|
}
|
|
|
|
kobject_uevent(&priv->kobj, KOBJ_ADD);
|
|
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_attrs(drv->bus, drv);
|
|
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 */
|
|
down(&dev->parent->sem);
|
|
ret = device_attach(dev);
|
|
if (dev->parent)
|
|
up(&dev->parent->sem);
|
|
}
|
|
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 */
|
|
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);
|
|
|
|
/**
|
|
* 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 */
|
|
|
|
|
|
/**
|
|
* 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++) {
|
|
error = bus_create_file(bus, &bus->bus_attrs[i]);
|
|
if (error)
|
|
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_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 bus with the system.
|
|
* @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.
|
|
*/
|
|
int bus_register(struct bus_type *bus)
|
|
{
|
|
int retval;
|
|
struct bus_type_private *priv;
|
|
|
|
priv = kzalloc(sizeof(struct bus_type_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;
|
|
}
|
|
|
|
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_attrs(bus);
|
|
if (retval)
|
|
goto bus_attrs_fail;
|
|
|
|
pr_debug("bus: '%s': registered\n", bus->name);
|
|
return 0;
|
|
|
|
bus_attrs_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);
|
|
kfree(bus->p);
|
|
out:
|
|
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);
|
|
bus_remove_attrs(bus);
|
|
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);
|
|
kfree(bus->p);
|
|
bus->p = NULL;
|
|
}
|
|
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 forcably 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);
|
|
|
|
int __init buses_init(void)
|
|
{
|
|
bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL);
|
|
if (!bus_kset)
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|