linux/drivers/rapidio/rio-driver.c
Greg Kroah-Hartman d69d804845 driver core: have match() callback in struct bus_type take a const *
In the match() callback, the struct device_driver * should not be
changed, so change the function callback to be a const *.  This is one
step of many towards making the driver core safe to have struct
device_driver in read-only memory.

Because the match() callback is in all busses, all busses are modified
to handle this properly.  This does entail switching some container_of()
calls to container_of_const() to properly handle the constant *.

For some busses, like PCI and USB and HV, the const * is cast away in
the match callback as those busses do want to modify those structures at
this point in time (they have a local lock in the driver structure.)
That will have to be changed in the future if they wish to have their
struct device * in read-only-memory.

Cc: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Alex Elder <elder@kernel.org>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-03 15:16:54 +02:00

267 lines
6.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* RapidIO driver support
*
* Copyright 2005 MontaVista Software, Inc.
* Matt Porter <mporter@kernel.crashing.org>
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/rio.h>
#include <linux/rio_ids.h>
#include <linux/rio_drv.h>
#include "rio.h"
/**
* rio_match_device - Tell if a RIO device has a matching RIO device id structure
* @id: the RIO device id structure to match against
* @rdev: the RIO device structure to match against
*
* Used from driver probe and bus matching to check whether a RIO device
* matches a device id structure provided by a RIO driver. Returns the
* matching &struct rio_device_id or %NULL if there is no match.
*/
static const struct rio_device_id *rio_match_device(const struct rio_device_id
*id,
const struct rio_dev *rdev)
{
while (id->vid || id->asm_vid) {
if (((id->vid == RIO_ANY_ID) || (id->vid == rdev->vid)) &&
((id->did == RIO_ANY_ID) || (id->did == rdev->did)) &&
((id->asm_vid == RIO_ANY_ID)
|| (id->asm_vid == rdev->asm_vid))
&& ((id->asm_did == RIO_ANY_ID)
|| (id->asm_did == rdev->asm_did)))
return id;
id++;
}
return NULL;
}
/**
* rio_dev_get - Increments the reference count of the RIO device structure
*
* @rdev: RIO device being referenced
*
* Each live reference to a device should be refcounted.
*
* Drivers for RIO devices should normally record such references in
* their probe() methods, when they bind to a device, and release
* them by calling rio_dev_put(), in their disconnect() methods.
*/
struct rio_dev *rio_dev_get(struct rio_dev *rdev)
{
if (rdev)
get_device(&rdev->dev);
return rdev;
}
/**
* rio_dev_put - Release a use of the RIO device structure
*
* @rdev: RIO device being disconnected
*
* Must be called when a user of a device is finished with it.
* When the last user of the device calls this function, the
* memory of the device is freed.
*/
void rio_dev_put(struct rio_dev *rdev)
{
if (rdev)
put_device(&rdev->dev);
}
/**
* rio_device_probe - Tell if a RIO device structure has a matching RIO device id structure
* @dev: the RIO device structure to match against
*
* return 0 and set rio_dev->driver when drv claims rio_dev, else error
*/
static int rio_device_probe(struct device *dev)
{
struct rio_driver *rdrv = to_rio_driver(dev->driver);
struct rio_dev *rdev = to_rio_dev(dev);
int error = -ENODEV;
const struct rio_device_id *id;
if (!rdev->driver && rdrv->probe) {
if (!rdrv->id_table)
return error;
id = rio_match_device(rdrv->id_table, rdev);
rio_dev_get(rdev);
if (id)
error = rdrv->probe(rdev, id);
if (error >= 0) {
rdev->driver = rdrv;
error = 0;
} else
rio_dev_put(rdev);
}
return error;
}
/**
* rio_device_remove - Remove a RIO device from the system
*
* @dev: the RIO device structure to match against
*
* Remove a RIO device from the system. If it has an associated
* driver, then run the driver remove() method. Then update
* the reference count.
*/
static void rio_device_remove(struct device *dev)
{
struct rio_dev *rdev = to_rio_dev(dev);
struct rio_driver *rdrv = rdev->driver;
if (rdrv) {
if (rdrv->remove)
rdrv->remove(rdev);
rdev->driver = NULL;
}
rio_dev_put(rdev);
}
static void rio_device_shutdown(struct device *dev)
{
struct rio_dev *rdev = to_rio_dev(dev);
struct rio_driver *rdrv = rdev->driver;
dev_dbg(dev, "RIO: %s\n", __func__);
if (rdrv && rdrv->shutdown)
rdrv->shutdown(rdev);
}
/**
* rio_register_driver - register a new RIO driver
* @rdrv: the RIO driver structure to register
*
* Adds a &struct rio_driver to the list of registered drivers.
* Returns a negative value on error, otherwise 0. If no error
* occurred, the driver remains registered even if no device
* was claimed during registration.
*/
int rio_register_driver(struct rio_driver *rdrv)
{
/* initialize common driver fields */
rdrv->driver.name = rdrv->name;
rdrv->driver.bus = &rio_bus_type;
/* register with core */
return driver_register(&rdrv->driver);
}
/**
* rio_unregister_driver - unregister a RIO driver
* @rdrv: the RIO driver structure to unregister
*
* Deletes the &struct rio_driver from the list of registered RIO
* drivers, gives it a chance to clean up by calling its remove()
* function for each device it was responsible for, and marks those
* devices as driverless.
*/
void rio_unregister_driver(struct rio_driver *rdrv)
{
driver_unregister(&rdrv->driver);
}
void rio_attach_device(struct rio_dev *rdev)
{
rdev->dev.bus = &rio_bus_type;
}
EXPORT_SYMBOL_GPL(rio_attach_device);
/**
* rio_match_bus - Tell if a RIO device structure has a matching RIO driver device id structure
* @dev: the standard device structure to match against
* @drv: the standard driver structure containing the ids to match against
*
* Used by a driver to check whether a RIO device present in the
* system is in its list of supported devices. Returns 1 if
* there is a matching &struct rio_device_id or 0 if there is
* no match.
*/
static int rio_match_bus(struct device *dev, const struct device_driver *drv)
{
struct rio_dev *rdev = to_rio_dev(dev);
const struct rio_driver *rdrv = to_rio_driver(drv);
const struct rio_device_id *id = rdrv->id_table;
const struct rio_device_id *found_id;
if (!id)
goto out;
found_id = rio_match_device(id, rdev);
if (found_id)
return 1;
out:return 0;
}
static int rio_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
const struct rio_dev *rdev;
if (!dev)
return -ENODEV;
rdev = to_rio_dev(dev);
if (!rdev)
return -ENODEV;
if (add_uevent_var(env, "MODALIAS=rapidio:v%04Xd%04Xav%04Xad%04X",
rdev->vid, rdev->did, rdev->asm_vid, rdev->asm_did))
return -ENOMEM;
return 0;
}
struct class rio_mport_class = {
.name = "rapidio_port",
.dev_groups = rio_mport_groups,
};
EXPORT_SYMBOL_GPL(rio_mport_class);
struct bus_type rio_bus_type = {
.name = "rapidio",
.match = rio_match_bus,
.dev_groups = rio_dev_groups,
.bus_groups = rio_bus_groups,
.probe = rio_device_probe,
.remove = rio_device_remove,
.shutdown = rio_device_shutdown,
.uevent = rio_uevent,
};
/**
* rio_bus_init - Register the RapidIO bus with the device model
*
* Registers the RIO mport device class and RIO bus type with the Linux
* device model.
*/
static int __init rio_bus_init(void)
{
int ret;
ret = class_register(&rio_mport_class);
if (!ret) {
ret = bus_register(&rio_bus_type);
if (ret)
class_unregister(&rio_mport_class);
}
return ret;
}
postcore_initcall(rio_bus_init);
EXPORT_SYMBOL_GPL(rio_register_driver);
EXPORT_SYMBOL_GPL(rio_unregister_driver);
EXPORT_SYMBOL_GPL(rio_bus_type);
EXPORT_SYMBOL_GPL(rio_dev_get);
EXPORT_SYMBOL_GPL(rio_dev_put);