linux/drivers/tc/tc-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

110 lines
3.0 KiB
C

/*
* TURBOchannel driver services.
*
* Copyright (c) 2005 James Simmons
* Copyright (c) 2006 Maciej W. Rozycki
*
* Loosely based on drivers/dio/dio-driver.c and
* drivers/pci/pci-driver.c.
*
* This file is subject to the terms and conditions of the GNU
* General Public License. See the file "COPYING" in the main
* directory of this archive for more details.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/tc.h>
/**
* tc_register_driver - register a new TC driver
* @drv: the driver structure to register
*
* Adds the driver structure 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 tc_register_driver(struct tc_driver *tdrv)
{
return driver_register(&tdrv->driver);
}
EXPORT_SYMBOL(tc_register_driver);
/**
* tc_unregister_driver - unregister a TC driver
* @drv: the driver structure to unregister
*
* Deletes the driver structure from the list of registered TC 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 tc_unregister_driver(struct tc_driver *tdrv)
{
driver_unregister(&tdrv->driver);
}
EXPORT_SYMBOL(tc_unregister_driver);
/**
* tc_match_device - tell if a TC device structure has a matching
* TC device ID structure
* @tdrv: the TC driver to earch for matching TC device ID strings
* @tdev: the TC device structure to match against
*
* Used by a driver to check whether a TC device present in the
* system is in its list of supported devices. Returns the matching
* tc_device_id structure or %NULL if there is no match.
*/
static const struct tc_device_id *tc_match_device(const struct tc_driver *tdrv,
struct tc_dev *tdev)
{
const struct tc_device_id *id = tdrv->id_table;
if (id) {
while (id->name[0] || id->vendor[0]) {
if (strcmp(tdev->name, id->name) == 0 &&
strcmp(tdev->vendor, id->vendor) == 0)
return id;
id++;
}
}
return NULL;
}
/**
* tc_bus_match - Tell if a device structure has a matching
* TC device ID structure
* @dev: the device structure to match against
* @drv: the device driver to search for matching TC device ID strings
*
* Used by a driver to check whether a TC device present in the
* system is in its list of supported devices. Returns 1 if there
* is a match or 0 otherwise.
*/
static int tc_bus_match(struct device *dev, const struct device_driver *drv)
{
struct tc_dev *tdev = to_tc_dev(dev);
const struct tc_driver *tdrv = to_tc_driver(drv);
const struct tc_device_id *id;
id = tc_match_device(tdrv, tdev);
if (id)
return 1;
return 0;
}
const struct bus_type tc_bus_type = {
.name = "tc",
.match = tc_bus_match,
};
EXPORT_SYMBOL(tc_bus_type);
static int __init tc_driver_init(void)
{
return bus_register(&tc_bus_type);
}
postcore_initcall(tc_driver_init);