mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 14:46:39 +07:00
7bc364097a
mcb_probe() does not aqcuire a reference to the probed device but drops one when removing the device. As it is actually using the device, it should grab a reference via get_device(). This could lead to a panic found with a rmmod/modprobe stress test Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reported-by: Andreas Werner <andreas.werner@men.de> Tested-by: Andreas Werner <andreas.werner@men.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
508 lines
10 KiB
C
508 lines
10 KiB
C
/*
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* MEN Chameleon Bus.
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*
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* Copyright (C) 2013 MEN Mikroelektronik GmbH (www.men.de)
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* Author: Johannes Thumshirn <johannes.thumshirn@men.de>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; version 2 of the License.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <linux/idr.h>
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#include <linux/mcb.h>
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static DEFINE_IDA(mcb_ida);
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static const struct mcb_device_id *mcb_match_id(const struct mcb_device_id *ids,
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struct mcb_device *dev)
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{
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if (ids) {
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while (ids->device) {
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if (ids->device == dev->id)
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return ids;
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ids++;
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}
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}
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return NULL;
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}
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static int mcb_match(struct device *dev, struct device_driver *drv)
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{
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struct mcb_driver *mdrv = to_mcb_driver(drv);
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struct mcb_device *mdev = to_mcb_device(dev);
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const struct mcb_device_id *found_id;
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found_id = mcb_match_id(mdrv->id_table, mdev);
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if (found_id)
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return 1;
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return 0;
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}
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static int mcb_uevent(struct device *dev, struct kobj_uevent_env *env)
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{
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struct mcb_device *mdev = to_mcb_device(dev);
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int ret;
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ret = add_uevent_var(env, "MODALIAS=mcb:16z%03d", mdev->id);
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if (ret)
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return -ENOMEM;
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return 0;
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}
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static int mcb_probe(struct device *dev)
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{
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struct mcb_driver *mdrv = to_mcb_driver(dev->driver);
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struct mcb_device *mdev = to_mcb_device(dev);
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const struct mcb_device_id *found_id;
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found_id = mcb_match_id(mdrv->id_table, mdev);
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if (!found_id)
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return -ENODEV;
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get_device(dev);
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return mdrv->probe(mdev, found_id);
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}
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static int mcb_remove(struct device *dev)
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{
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struct mcb_driver *mdrv = to_mcb_driver(dev->driver);
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struct mcb_device *mdev = to_mcb_device(dev);
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mdrv->remove(mdev);
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put_device(&mdev->dev);
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return 0;
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}
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static void mcb_shutdown(struct device *dev)
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{
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struct mcb_driver *mdrv = to_mcb_driver(dev->driver);
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struct mcb_device *mdev = to_mcb_device(dev);
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if (mdrv && mdrv->shutdown)
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mdrv->shutdown(mdev);
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}
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static ssize_t revision_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct mcb_bus *bus = to_mcb_bus(dev);
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return scnprintf(buf, PAGE_SIZE, "%d\n", bus->revision);
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}
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static DEVICE_ATTR_RO(revision);
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static ssize_t model_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct mcb_bus *bus = to_mcb_bus(dev);
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return scnprintf(buf, PAGE_SIZE, "%c\n", bus->model);
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}
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static DEVICE_ATTR_RO(model);
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static ssize_t minor_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct mcb_bus *bus = to_mcb_bus(dev);
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return scnprintf(buf, PAGE_SIZE, "%d\n", bus->minor);
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}
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static DEVICE_ATTR_RO(minor);
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static ssize_t name_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct mcb_bus *bus = to_mcb_bus(dev);
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return scnprintf(buf, PAGE_SIZE, "%s\n", bus->name);
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}
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static DEVICE_ATTR_RO(name);
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static struct attribute *mcb_bus_attrs[] = {
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&dev_attr_revision.attr,
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&dev_attr_model.attr,
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&dev_attr_minor.attr,
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&dev_attr_name.attr,
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NULL,
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};
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static const struct attribute_group mcb_carrier_group = {
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.attrs = mcb_bus_attrs,
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};
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static const struct attribute_group *mcb_carrier_groups[] = {
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&mcb_carrier_group,
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NULL,
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};
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static struct bus_type mcb_bus_type = {
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.name = "mcb",
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.match = mcb_match,
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.uevent = mcb_uevent,
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.probe = mcb_probe,
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.remove = mcb_remove,
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.shutdown = mcb_shutdown,
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};
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static struct device_type mcb_carrier_device_type = {
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.name = "mcb-carrier",
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.groups = mcb_carrier_groups,
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};
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/**
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* __mcb_register_driver() - Register a @mcb_driver at the system
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* @drv: The @mcb_driver
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* @owner: The @mcb_driver's module
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* @mod_name: The name of the @mcb_driver's module
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*
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* Register a @mcb_driver at the system. Perform some sanity checks, if
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* the .probe and .remove methods are provided by the driver.
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*/
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int __mcb_register_driver(struct mcb_driver *drv, struct module *owner,
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const char *mod_name)
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{
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if (!drv->probe || !drv->remove)
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return -EINVAL;
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drv->driver.owner = owner;
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drv->driver.bus = &mcb_bus_type;
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drv->driver.mod_name = mod_name;
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return driver_register(&drv->driver);
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}
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EXPORT_SYMBOL_GPL(__mcb_register_driver);
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/**
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* mcb_unregister_driver() - Unregister a @mcb_driver from the system
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* @drv: The @mcb_driver
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*
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* Unregister a @mcb_driver from the system.
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*/
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void mcb_unregister_driver(struct mcb_driver *drv)
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{
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driver_unregister(&drv->driver);
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}
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EXPORT_SYMBOL_GPL(mcb_unregister_driver);
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static void mcb_release_dev(struct device *dev)
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{
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struct mcb_device *mdev = to_mcb_device(dev);
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mcb_bus_put(mdev->bus);
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kfree(mdev);
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}
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/**
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* mcb_device_register() - Register a mcb_device
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* @bus: The @mcb_bus of the device
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* @dev: The @mcb_device
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*
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* Register a specific @mcb_device at a @mcb_bus and the system itself.
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*/
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int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev)
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{
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int ret;
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int device_id;
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device_initialize(&dev->dev);
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mcb_bus_get(bus);
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dev->dev.bus = &mcb_bus_type;
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dev->dev.parent = bus->dev.parent;
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dev->dev.release = mcb_release_dev;
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device_id = dev->id;
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dev_set_name(&dev->dev, "mcb%d-16z%03d-%d:%d:%d",
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bus->bus_nr, device_id, dev->inst, dev->group, dev->var);
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ret = device_add(&dev->dev);
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if (ret < 0) {
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pr_err("Failed registering device 16z%03d on bus mcb%d (%d)\n",
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device_id, bus->bus_nr, ret);
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goto out;
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}
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return 0;
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out:
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return ret;
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}
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EXPORT_SYMBOL_GPL(mcb_device_register);
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static void mcb_free_bus(struct device *dev)
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{
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struct mcb_bus *bus = to_mcb_bus(dev);
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put_device(bus->carrier);
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ida_simple_remove(&mcb_ida, bus->bus_nr);
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kfree(bus);
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}
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/**
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* mcb_alloc_bus() - Allocate a new @mcb_bus
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*
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* Allocate a new @mcb_bus.
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*/
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struct mcb_bus *mcb_alloc_bus(struct device *carrier)
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{
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struct mcb_bus *bus;
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int bus_nr;
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int rc;
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bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL);
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if (!bus)
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return ERR_PTR(-ENOMEM);
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bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL);
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if (bus_nr < 0) {
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rc = bus_nr;
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goto err_free;
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}
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bus->bus_nr = bus_nr;
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bus->carrier = get_device(carrier);
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device_initialize(&bus->dev);
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bus->dev.parent = carrier;
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bus->dev.bus = &mcb_bus_type;
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bus->dev.type = &mcb_carrier_device_type;
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bus->dev.release = &mcb_free_bus;
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dev_set_name(&bus->dev, "mcb:%d", bus_nr);
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rc = device_add(&bus->dev);
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if (rc)
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goto err_free;
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return bus;
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err_free:
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put_device(carrier);
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kfree(bus);
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return ERR_PTR(rc);
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}
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EXPORT_SYMBOL_GPL(mcb_alloc_bus);
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static int __mcb_devices_unregister(struct device *dev, void *data)
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{
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device_unregister(dev);
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return 0;
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}
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static void mcb_devices_unregister(struct mcb_bus *bus)
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{
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bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_devices_unregister);
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}
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/**
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* mcb_release_bus() - Free a @mcb_bus
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* @bus: The @mcb_bus to release
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*
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* Release an allocated @mcb_bus from the system.
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*/
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void mcb_release_bus(struct mcb_bus *bus)
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{
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mcb_devices_unregister(bus);
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}
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EXPORT_SYMBOL_GPL(mcb_release_bus);
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/**
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* mcb_bus_put() - Increment refcnt
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* @bus: The @mcb_bus
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*
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* Get a @mcb_bus' ref
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*/
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struct mcb_bus *mcb_bus_get(struct mcb_bus *bus)
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{
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if (bus)
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get_device(&bus->dev);
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return bus;
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}
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EXPORT_SYMBOL_GPL(mcb_bus_get);
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/**
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* mcb_bus_put() - Decrement refcnt
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* @bus: The @mcb_bus
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*
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* Release a @mcb_bus' ref
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*/
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void mcb_bus_put(struct mcb_bus *bus)
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{
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if (bus)
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put_device(&bus->dev);
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}
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EXPORT_SYMBOL_GPL(mcb_bus_put);
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/**
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* mcb_alloc_dev() - Allocate a device
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* @bus: The @mcb_bus the device is part of
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*
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* Allocate a @mcb_device and add bus.
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*/
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struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus)
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{
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struct mcb_device *dev;
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dev = kzalloc(sizeof(struct mcb_device), GFP_KERNEL);
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if (!dev)
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return NULL;
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INIT_LIST_HEAD(&dev->bus_list);
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dev->bus = bus;
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return dev;
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}
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EXPORT_SYMBOL_GPL(mcb_alloc_dev);
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/**
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* mcb_free_dev() - Free @mcb_device
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* @dev: The device to free
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*
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* Free a @mcb_device
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*/
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void mcb_free_dev(struct mcb_device *dev)
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{
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kfree(dev);
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}
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EXPORT_SYMBOL_GPL(mcb_free_dev);
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static int __mcb_bus_add_devices(struct device *dev, void *data)
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{
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struct mcb_device *mdev = to_mcb_device(dev);
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int retval;
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if (mdev->is_added)
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return 0;
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retval = device_attach(dev);
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if (retval < 0)
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dev_err(dev, "Error adding device (%d)\n", retval);
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mdev->is_added = true;
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return 0;
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}
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static int __mcb_bus_add_child(struct device *dev, void *data)
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{
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struct mcb_device *mdev = to_mcb_device(dev);
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struct mcb_bus *child;
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BUG_ON(!mdev->is_added);
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child = mdev->subordinate;
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if (child)
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mcb_bus_add_devices(child);
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return 0;
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}
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/**
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* mcb_bus_add_devices() - Add devices in the bus' internal device list
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* @bus: The @mcb_bus we add the devices
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*
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* Add devices in the bus' internal device list to the system.
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*/
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void mcb_bus_add_devices(const struct mcb_bus *bus)
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{
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bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_devices);
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bus_for_each_dev(&mcb_bus_type, NULL, NULL, __mcb_bus_add_child);
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}
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EXPORT_SYMBOL_GPL(mcb_bus_add_devices);
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/**
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* mcb_request_mem() - Request memory
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* @dev: The @mcb_device the memory is for
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* @name: The name for the memory reference.
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*
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* Request memory for a @mcb_device. If @name is NULL the driver name will
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* be used.
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*/
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struct resource *mcb_request_mem(struct mcb_device *dev, const char *name)
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{
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struct resource *mem;
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u32 size;
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if (!name)
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name = dev->dev.driver->name;
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size = resource_size(&dev->mem);
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mem = request_mem_region(dev->mem.start, size, name);
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if (!mem)
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return ERR_PTR(-EBUSY);
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return mem;
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}
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EXPORT_SYMBOL_GPL(mcb_request_mem);
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/**
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* mcb_release_mem() - Release memory requested by device
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* @dev: The @mcb_device that requested the memory
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*
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* Release memory that was prior requested via @mcb_request_mem().
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*/
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void mcb_release_mem(struct resource *mem)
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{
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u32 size;
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size = resource_size(mem);
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release_mem_region(mem->start, size);
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}
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EXPORT_SYMBOL_GPL(mcb_release_mem);
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static int __mcb_get_irq(struct mcb_device *dev)
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{
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struct resource *irq = &dev->irq;
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return irq->start;
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}
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/**
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* mcb_get_irq() - Get device's IRQ number
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* @dev: The @mcb_device the IRQ is for
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*
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* Get the IRQ number of a given @mcb_device.
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*/
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int mcb_get_irq(struct mcb_device *dev)
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{
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struct mcb_bus *bus = dev->bus;
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if (bus->get_irq)
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return bus->get_irq(dev);
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return __mcb_get_irq(dev);
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}
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EXPORT_SYMBOL_GPL(mcb_get_irq);
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static int mcb_init(void)
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{
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return bus_register(&mcb_bus_type);
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}
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static void mcb_exit(void)
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{
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ida_destroy(&mcb_ida);
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bus_unregister(&mcb_bus_type);
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}
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/* mcb must be initialized after PCI but before the chameleon drivers.
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* That means we must use some initcall between subsys_initcall and
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* device_initcall.
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*/
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fs_initcall(mcb_init);
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module_exit(mcb_exit);
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MODULE_DESCRIPTION("MEN Chameleon Bus Driver");
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MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>");
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MODULE_LICENSE("GPL v2");
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