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![Eugene Surovegin](/assets/img/avatar_default.png)
Fix RapidIO device reference counting. Signed-of-by: Eugene Surovegin <ebs@ebshome.net> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
227 lines
6 KiB
C
227 lines
6 KiB
C
/*
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* RapidIO driver support
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*
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* Copyright 2005 MontaVista Software, Inc.
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* Matt Porter <mporter@kernel.crashing.org>
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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
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/rio.h>
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#include <linux/rio_ids.h>
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#include "rio.h"
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/**
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* rio_match_device - Tell if a RIO device has a matching RIO device id structure
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* @id: the RIO device id structure to match against
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* @rdev: the RIO device structure to match against
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*
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* Used from driver probe and bus matching to check whether a RIO device
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* matches a device id structure provided by a RIO driver. Returns the
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* matching &struct rio_device_id or %NULL if there is no match.
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*/
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static const struct rio_device_id *rio_match_device(const struct rio_device_id
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*id,
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const struct rio_dev *rdev)
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{
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while (id->vid || id->asm_vid) {
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if (((id->vid == RIO_ANY_ID) || (id->vid == rdev->vid)) &&
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((id->did == RIO_ANY_ID) || (id->did == rdev->did)) &&
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((id->asm_vid == RIO_ANY_ID)
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|| (id->asm_vid == rdev->asm_vid))
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&& ((id->asm_did == RIO_ANY_ID)
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|| (id->asm_did == rdev->asm_did)))
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return id;
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id++;
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}
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return NULL;
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}
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/**
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* rio_dev_get - Increments the reference count of the RIO device structure
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*
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* @rdev: RIO device being referenced
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*
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* Each live reference to a device should be refcounted.
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*
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* Drivers for RIO devices should normally record such references in
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* their probe() methods, when they bind to a device, and release
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* them by calling rio_dev_put(), in their disconnect() methods.
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*/
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struct rio_dev *rio_dev_get(struct rio_dev *rdev)
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{
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if (rdev)
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get_device(&rdev->dev);
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return rdev;
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}
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/**
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* rio_dev_put - Release a use of the RIO device structure
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*
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* @rdev: RIO device being disconnected
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*
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* Must be called when a user of a device is finished with it.
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* When the last user of the device calls this function, the
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* memory of the device is freed.
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*/
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void rio_dev_put(struct rio_dev *rdev)
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{
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if (rdev)
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put_device(&rdev->dev);
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}
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/**
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* rio_device_probe - Tell if a RIO device structure has a matching RIO device id structure
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* @id: the RIO device id structure to match against
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* @dev: the RIO device structure to match against
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*
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* return 0 and set rio_dev->driver when drv claims rio_dev, else error
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*/
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static int rio_device_probe(struct device *dev)
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{
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struct rio_driver *rdrv = to_rio_driver(dev->driver);
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struct rio_dev *rdev = to_rio_dev(dev);
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int error = -ENODEV;
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const struct rio_device_id *id;
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if (!rdev->driver && rdrv->probe) {
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if (!rdrv->id_table)
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return error;
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id = rio_match_device(rdrv->id_table, rdev);
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rio_dev_get(rdev);
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if (id)
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error = rdrv->probe(rdev, id);
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if (error >= 0) {
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rdev->driver = rdrv;
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error = 0;
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} else
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rio_dev_put(rdev);
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}
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return error;
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}
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/**
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* rio_device_remove - Remove a RIO device from the system
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*
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* @dev: the RIO device structure to match against
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*
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* Remove a RIO device from the system. If it has an associated
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* driver, then run the driver remove() method. Then update
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* the reference count.
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*/
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static int rio_device_remove(struct device *dev)
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{
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struct rio_dev *rdev = to_rio_dev(dev);
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struct rio_driver *rdrv = rdev->driver;
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if (rdrv) {
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if (rdrv->remove)
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rdrv->remove(rdev);
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rdev->driver = NULL;
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}
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rio_dev_put(rdev);
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return 0;
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}
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/**
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* rio_register_driver - register a new RIO driver
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* @rdrv: the RIO driver structure to register
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*
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* Adds a &struct rio_driver to the list of registered drivers.
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* Returns a negative value on error, otherwise 0. If no error
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* occurred, the driver remains registered even if no device
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* was claimed during registration.
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*/
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int rio_register_driver(struct rio_driver *rdrv)
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{
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/* initialize common driver fields */
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rdrv->driver.name = rdrv->name;
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rdrv->driver.bus = &rio_bus_type;
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/* register with core */
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return driver_register(&rdrv->driver);
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}
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/**
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* rio_unregister_driver - unregister a RIO driver
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* @rdrv: the RIO driver structure to unregister
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*
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* Deletes the &struct rio_driver from the list of registered RIO
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* drivers, gives it a chance to clean up by calling its remove()
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* function for each device it was responsible for, and marks those
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* devices as driverless.
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*/
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void rio_unregister_driver(struct rio_driver *rdrv)
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{
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driver_unregister(&rdrv->driver);
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}
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/**
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* rio_match_bus - Tell if a RIO device structure has a matching RIO driver device id structure
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* @dev: the standard device structure to match against
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* @drv: the standard driver structure containing the ids to match against
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*
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* Used by a driver to check whether a RIO device present in the
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* system is in its list of supported devices. Returns 1 if
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* there is a matching &struct rio_device_id or 0 if there is
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* no match.
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*/
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static int rio_match_bus(struct device *dev, struct device_driver *drv)
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{
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struct rio_dev *rdev = to_rio_dev(dev);
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struct rio_driver *rdrv = to_rio_driver(drv);
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const struct rio_device_id *id = rdrv->id_table;
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const struct rio_device_id *found_id;
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if (!id)
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goto out;
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found_id = rio_match_device(id, rdev);
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if (found_id)
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return 1;
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out:return 0;
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}
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static struct device rio_bus = {
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.bus_id = "rapidio",
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};
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struct bus_type rio_bus_type = {
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.name = "rapidio",
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.match = rio_match_bus,
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.dev_attrs = rio_dev_attrs,
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.probe = rio_device_probe,
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.remove = rio_device_remove,
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};
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/**
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* rio_bus_init - Register the RapidIO bus with the device model
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*
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* Registers the RIO bus device and RIO bus type with the Linux
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* device model.
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*/
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static int __init rio_bus_init(void)
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{
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if (device_register(&rio_bus) < 0)
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printk("RIO: failed to register RIO bus device\n");
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return bus_register(&rio_bus_type);
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}
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postcore_initcall(rio_bus_init);
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EXPORT_SYMBOL_GPL(rio_register_driver);
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EXPORT_SYMBOL_GPL(rio_unregister_driver);
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EXPORT_SYMBOL_GPL(rio_bus_type);
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EXPORT_SYMBOL_GPL(rio_dev_get);
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EXPORT_SYMBOL_GPL(rio_dev_put);
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