linux/drivers/dma/idxd/bus.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

97 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2021 Intel Corporation. All rights rsvd. */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include "idxd.h"
int __idxd_driver_register(struct idxd_device_driver *idxd_drv, struct module *owner,
const char *mod_name)
{
struct device_driver *drv = &idxd_drv->drv;
if (!idxd_drv->type) {
pr_debug("driver type not set (%ps)\n", __builtin_return_address(0));
return -EINVAL;
}
drv->name = idxd_drv->name;
drv->bus = &dsa_bus_type;
drv->owner = owner;
drv->mod_name = mod_name;
return driver_register(drv);
}
EXPORT_SYMBOL_GPL(__idxd_driver_register);
void idxd_driver_unregister(struct idxd_device_driver *idxd_drv)
{
driver_unregister(&idxd_drv->drv);
}
EXPORT_SYMBOL_GPL(idxd_driver_unregister);
static int idxd_config_bus_match(struct device *dev,
const struct device_driver *drv)
{
const struct idxd_device_driver *idxd_drv =
container_of_const(drv, struct idxd_device_driver, drv);
struct idxd_dev *idxd_dev = confdev_to_idxd_dev(dev);
int i = 0;
while (idxd_drv->type[i] != IDXD_DEV_NONE) {
if (idxd_dev->type == idxd_drv->type[i])
return 1;
i++;
}
return 0;
}
static int idxd_config_bus_probe(struct device *dev)
{
struct idxd_device_driver *idxd_drv =
container_of(dev->driver, struct idxd_device_driver, drv);
struct idxd_dev *idxd_dev = confdev_to_idxd_dev(dev);
return idxd_drv->probe(idxd_dev);
}
static void idxd_config_bus_remove(struct device *dev)
{
struct idxd_device_driver *idxd_drv =
container_of(dev->driver, struct idxd_device_driver, drv);
struct idxd_dev *idxd_dev = confdev_to_idxd_dev(dev);
idxd_drv->remove(idxd_dev);
}
static int idxd_bus_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
return add_uevent_var(env, "MODALIAS=" IDXD_DEVICES_MODALIAS_FMT, 0);
}
const struct bus_type dsa_bus_type = {
.name = "dsa",
.match = idxd_config_bus_match,
.probe = idxd_config_bus_probe,
.remove = idxd_config_bus_remove,
.uevent = idxd_bus_uevent,
};
EXPORT_SYMBOL_GPL(dsa_bus_type);
static int __init dsa_bus_init(void)
{
return bus_register(&dsa_bus_type);
}
module_init(dsa_bus_init);
static void __exit dsa_bus_exit(void)
{
bus_unregister(&dsa_bus_type);
}
module_exit(dsa_bus_exit);
MODULE_DESCRIPTION("IDXD driver dsa_bus_type driver");
MODULE_LICENSE("GPL v2");