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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright(c) 2015 - 2019 Intel Corporation. All rights reserved.
* Copyright(c) 2021 - 2024 Linaro Ltd.
*/
#include <linux/device.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/rpmb.h>
#include <linux/slab.h>
static DEFINE_IDA(rpmb_ida);
static DEFINE_MUTEX(rpmb_mutex);
/**
* rpmb_dev_get() - increase rpmb device ref counter
* @rdev: rpmb device
*/
struct rpmb_dev *rpmb_dev_get(struct rpmb_dev *rdev)
{
if (rdev)
get_device(&rdev->dev);
return rdev;
}
EXPORT_SYMBOL_GPL(rpmb_dev_get);
/**
* rpmb_dev_put() - decrease rpmb device ref counter
* @rdev: rpmb device
*/
void rpmb_dev_put(struct rpmb_dev *rdev)
{
if (rdev)
put_device(&rdev->dev);
}
EXPORT_SYMBOL_GPL(rpmb_dev_put);
/**
* rpmb_route_frames() - route rpmb frames to rpmb device
* @rdev: rpmb device
* @req: rpmb request frames
* @req_len: length of rpmb request frames in bytes
* @rsp: rpmb response frames
* @rsp_len: length of rpmb response frames in bytes
*
* Returns: < 0 on failure
*/
int rpmb_route_frames(struct rpmb_dev *rdev, u8 *req,
unsigned int req_len, u8 *rsp, unsigned int rsp_len)
{
if (!req || !req_len || !rsp || !rsp_len)
return -EINVAL;
return rdev->descr.route_frames(rdev->dev.parent, req, req_len,
rsp, rsp_len);
}
EXPORT_SYMBOL_GPL(rpmb_route_frames);
static void rpmb_dev_release(struct device *dev)
{
struct rpmb_dev *rdev = to_rpmb_dev(dev);
mutex_lock(&rpmb_mutex);
ida_simple_remove(&rpmb_ida, rdev->id);
mutex_unlock(&rpmb_mutex);
kfree(rdev->descr.dev_id);
kfree(rdev);
}
static struct class rpmb_class = {
.name = "rpmb",
.dev_release = rpmb_dev_release,
};
/**
* rpmb_dev_find_device() - return first matching rpmb device
* @start: rpmb device to begin with
* @data: data for the match function
* @match: the matching function
*
* Iterate over registered RPMB devices, and call @match() for each passing
* it the RPMB device and @data.
*
* The return value of @match() is checked for each call. If it returns
* anything other 0, break and return the found RPMB device.
*
* It's the callers responsibility to call rpmb_dev_put() on the returned
* device, when it's done with it.
*
* Returns: a matching rpmb device or NULL on failure
*/
struct rpmb_dev *rpmb_dev_find_device(const void *data,
const struct rpmb_dev *start,
int (*match)(struct device *dev,
const void *data))
{
struct device *dev;
const struct device *start_dev = NULL;
if (start)
start_dev = &start->dev;
dev = class_find_device(&rpmb_class, start_dev, data, match);
return dev ? to_rpmb_dev(dev) : NULL;
}
EXPORT_SYMBOL_GPL(rpmb_dev_find_device);
int rpmb_interface_register(struct class_interface *intf)
{
intf->class = &rpmb_class;
return class_interface_register(intf);
}
EXPORT_SYMBOL_GPL(rpmb_interface_register);
void rpmb_interface_unregister(struct class_interface *intf)
{
class_interface_unregister(intf);
}
EXPORT_SYMBOL_GPL(rpmb_interface_unregister);
/**
* rpmb_dev_unregister() - unregister RPMB partition from the RPMB subsystem
* @rdev: the rpmb device to unregister
*
* This function should be called from the release function of the
* underlying device used when the RPMB device was registered.
*
* Returns: < 0 on failure
*/
int rpmb_dev_unregister(struct rpmb_dev *rdev)
{
if (!rdev)
return -EINVAL;
device_del(&rdev->dev);
rpmb_dev_put(rdev);
return 0;
}
EXPORT_SYMBOL_GPL(rpmb_dev_unregister);
/**
* rpmb_dev_register - register RPMB partition with the RPMB subsystem
* @dev: storage device of the rpmb device
* @descr: RPMB device description
*
* While registering the RPMB partition extract needed device information
* while needed resources are available.
*
* Returns: a pointer to a 'struct rpmb_dev' or an ERR_PTR on failure
*/
struct rpmb_dev *rpmb_dev_register(struct device *dev,
struct rpmb_descr *descr)
{
struct rpmb_dev *rdev;
int ret;
if (!dev || !descr || !descr->route_frames || !descr->dev_id ||
!descr->dev_id_len)
return ERR_PTR(-EINVAL);
rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
if (!rdev)
return ERR_PTR(-ENOMEM);
rdev->descr = *descr;
rdev->descr.dev_id = kmemdup(descr->dev_id, descr->dev_id_len,
GFP_KERNEL);
if (!rdev->descr.dev_id) {
ret = -ENOMEM;
goto err_free_rdev;
}
mutex_lock(&rpmb_mutex);
ret = ida_simple_get(&rpmb_ida, 0, 0, GFP_KERNEL);
mutex_unlock(&rpmb_mutex);
if (ret < 0)
goto err_free_dev_id;
rdev->id = ret;
dev_set_name(&rdev->dev, "rpmb%d", rdev->id);
rdev->dev.class = &rpmb_class;
rdev->dev.parent = dev;
ret = device_register(&rdev->dev);
if (ret) {
put_device(&rdev->dev);
return ERR_PTR(ret);
}
dev_dbg(&rdev->dev, "registered device\n");
return rdev;
err_free_dev_id:
kfree(rdev->descr.dev_id);
err_free_rdev:
kfree(rdev);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(rpmb_dev_register);
static int __init rpmb_init(void)
{
int ret;
ret = class_register(&rpmb_class);
if (ret) {
pr_err("couldn't create class\n");
return ret;
}
ida_init(&rpmb_ida);
return 0;
}
static void __exit rpmb_exit(void)
{
ida_destroy(&rpmb_ida);
class_unregister(&rpmb_class);
}
subsys_initcall(rpmb_init);
module_exit(rpmb_exit);
MODULE_AUTHOR("Jens Wiklander <jens.wiklander@linaro.org>");
MODULE_DESCRIPTION("RPMB class");
MODULE_LICENSE("GPL");
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