1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright(c) 2015 - 2019 Intel Corporation. All rights reserved.
4 * Copyright(c) 2021 - 2024 Linaro Ltd.
5 */
6#include <linux/device.h>
7#include <linux/init.h>
8#include <linux/kernel.h>
9#include <linux/list.h>
10#include <linux/module.h>
11#include <linux/mutex.h>
12#include <linux/rpmb.h>
13#include <linux/slab.h>
14
15static DEFINE_IDA(rpmb_ida);
16
17/**
18 * rpmb_dev_get() - increase rpmb device ref counter
19 * @rdev: rpmb device
20 */
21struct rpmb_dev *rpmb_dev_get(struct rpmb_dev *rdev)
22{
23 if (rdev)
24 get_device(dev: &rdev->dev);
25 return rdev;
26}
27EXPORT_SYMBOL_GPL(rpmb_dev_get);
28
29/**
30 * rpmb_dev_put() - decrease rpmb device ref counter
31 * @rdev: rpmb device
32 */
33void rpmb_dev_put(struct rpmb_dev *rdev)
34{
35 if (rdev)
36 put_device(dev: &rdev->dev);
37}
38EXPORT_SYMBOL_GPL(rpmb_dev_put);
39
40/**
41 * rpmb_route_frames() - route rpmb frames to rpmb device
42 * @rdev: rpmb device
43 * @req: rpmb request frames
44 * @req_len: length of rpmb request frames in bytes
45 * @rsp: rpmb response frames
46 * @rsp_len: length of rpmb response frames in bytes
47 *
48 * Returns: < 0 on failure
49 */
50int rpmb_route_frames(struct rpmb_dev *rdev, u8 *req,
51 unsigned int req_len, u8 *rsp, unsigned int rsp_len)
52{
53 if (!req || !req_len || !rsp || !rsp_len)
54 return -EINVAL;
55
56 return rdev->descr.route_frames(rdev->dev.parent, req, req_len,
57 rsp, rsp_len);
58}
59EXPORT_SYMBOL_GPL(rpmb_route_frames);
60
61static void rpmb_dev_release(struct device *dev)
62{
63 struct rpmb_dev *rdev = to_rpmb_dev(dev);
64
65 ida_free(&rpmb_ida, id: rdev->id);
66 kfree(objp: rdev->descr.dev_id);
67 kfree(objp: rdev);
68}
69
70static struct class rpmb_class = {
71 .name = "rpmb",
72 .dev_release = rpmb_dev_release,
73};
74
75/**
76 * rpmb_dev_find_device() - return first matching rpmb device
77 * @start: rpmb device to begin with
78 * @data: data for the match function
79 * @match: the matching function
80 *
81 * Iterate over registered RPMB devices, and call @match() for each passing
82 * it the RPMB device and @data.
83 *
84 * The return value of @match() is checked for each call. If it returns
85 * anything other 0, break and return the found RPMB device.
86 *
87 * It's the callers responsibility to call rpmb_dev_put() on the returned
88 * device, when it's done with it.
89 *
90 * Returns: a matching rpmb device or NULL on failure
91 */
92struct rpmb_dev *rpmb_dev_find_device(const void *data,
93 const struct rpmb_dev *start,
94 int (*match)(struct device *dev,
95 const void *data))
96{
97 struct device *dev;
98 const struct device *start_dev = NULL;
99
100 if (start)
101 start_dev = &start->dev;
102 dev = class_find_device(class: &rpmb_class, start: start_dev, data, match);
103
104 return dev ? to_rpmb_dev(dev) : NULL;
105}
106EXPORT_SYMBOL_GPL(rpmb_dev_find_device);
107
108int rpmb_interface_register(struct class_interface *intf)
109{
110 intf->class = &rpmb_class;
111
112 return class_interface_register(intf);
113}
114EXPORT_SYMBOL_GPL(rpmb_interface_register);
115
116void rpmb_interface_unregister(struct class_interface *intf)
117{
118 class_interface_unregister(intf);
119}
120EXPORT_SYMBOL_GPL(rpmb_interface_unregister);
121
122/**
123 * rpmb_dev_unregister() - unregister RPMB partition from the RPMB subsystem
124 * @rdev: the rpmb device to unregister
125 *
126 * This function should be called from the release function of the
127 * underlying device used when the RPMB device was registered.
128 *
129 * Returns: < 0 on failure
130 */
131int rpmb_dev_unregister(struct rpmb_dev *rdev)
132{
133 if (!rdev)
134 return -EINVAL;
135
136 device_del(dev: &rdev->dev);
137
138 rpmb_dev_put(rdev);
139
140 return 0;
141}
142EXPORT_SYMBOL_GPL(rpmb_dev_unregister);
143
144/**
145 * rpmb_dev_register - register RPMB partition with the RPMB subsystem
146 * @dev: storage device of the rpmb device
147 * @descr: RPMB device description
148 *
149 * While registering the RPMB partition extract needed device information
150 * while needed resources are available.
151 *
152 * Returns: a pointer to a 'struct rpmb_dev' or an ERR_PTR on failure
153 */
154struct rpmb_dev *rpmb_dev_register(struct device *dev,
155 struct rpmb_descr *descr)
156{
157 struct rpmb_dev *rdev;
158 int ret;
159
160 if (!dev || !descr || !descr->route_frames || !descr->dev_id ||
161 !descr->dev_id_len)
162 return ERR_PTR(error: -EINVAL);
163
164 rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
165 if (!rdev)
166 return ERR_PTR(error: -ENOMEM);
167 rdev->descr = *descr;
168 rdev->descr.dev_id = kmemdup(descr->dev_id, descr->dev_id_len,
169 GFP_KERNEL);
170 if (!rdev->descr.dev_id) {
171 ret = -ENOMEM;
172 goto err_free_rdev;
173 }
174
175 ret = ida_alloc(ida: &rpmb_ida, GFP_KERNEL);
176 if (ret < 0)
177 goto err_free_dev_id;
178 rdev->id = ret;
179
180 dev_set_name(dev: &rdev->dev, name: "rpmb%d", rdev->id);
181 rdev->dev.class = &rpmb_class;
182 rdev->dev.parent = dev;
183
184 ret = device_register(dev: &rdev->dev);
185 if (ret) {
186 put_device(dev: &rdev->dev);
187 return ERR_PTR(error: ret);
188 }
189
190 dev_dbg(&rdev->dev, "registered device\n");
191
192 return rdev;
193
194err_free_dev_id:
195 kfree(objp: rdev->descr.dev_id);
196err_free_rdev:
197 kfree(objp: rdev);
198 return ERR_PTR(error: ret);
199}
200EXPORT_SYMBOL_GPL(rpmb_dev_register);
201
202static int __init rpmb_init(void)
203{
204 int ret;
205
206 ret = class_register(class: &rpmb_class);
207 if (ret) {
208 pr_err("couldn't create class\n");
209 return ret;
210 }
211 ida_init(ida: &rpmb_ida);
212 return 0;
213}
214
215static void __exit rpmb_exit(void)
216{
217 ida_destroy(ida: &rpmb_ida);
218 class_unregister(class: &rpmb_class);
219}
220
221subsys_initcall(rpmb_init);
222module_exit(rpmb_exit);
223
224MODULE_AUTHOR("Jens Wiklander <jens.wiklander@linaro.org>");
225MODULE_DESCRIPTION("RPMB class");
226MODULE_LICENSE("GPL");
227

source code of linux/drivers/misc/rpmb-core.c