diff options
Diffstat (limited to 'drivers/misc/rpmb-core.c')
| -rw-r--r-- | drivers/misc/rpmb-core.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/drivers/misc/rpmb-core.c b/drivers/misc/rpmb-core.c new file mode 100644 index 000000000000..bc68cde1a8bf --- /dev/null +++ b/drivers/misc/rpmb-core.c @@ -0,0 +1,231 @@ +// 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"); |