1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2022, STMicroelectronics
4 * Copyright (c) 2016, Linaro Ltd.
5 * Copyright (c) 2012, Michal Simek <monstr@monstr.eu>
6 * Copyright (c) 2012, PetaLogix
7 * Copyright (c) 2011, Texas Instruments, Inc.
8 * Copyright (c) 2011, Google, Inc.
9 *
10 * Based on rpmsg performance statistics driver by Michal Simek, which in turn
11 * was based on TI & Google OMX rpmsg driver.
12 */
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/cdev.h>
17#include <linux/device.h>
18#include <linux/fs.h>
19#include <linux/idr.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/rpmsg.h>
23#include <linux/skbuff.h>
24#include <linux/slab.h>
25#include <linux/uaccess.h>
26#include <uapi/linux/rpmsg.h>
27
28#include "rpmsg_char.h"
29#include "rpmsg_internal.h"
30
31#define RPMSG_DEV_MAX (MINORMASK + 1)
32
33static dev_t rpmsg_major;
34
35static DEFINE_IDA(rpmsg_ctrl_ida);
36static DEFINE_IDA(rpmsg_minor_ida);
37
38#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev)
39#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev)
40
41/**
42 * struct rpmsg_ctrldev - control device for instantiating endpoint devices
43 * @rpdev: underlaying rpmsg device
44 * @cdev: cdev for the ctrl device
45 * @dev: device for the ctrl device
46 * @ctrl_lock: serialize the ioctrls.
47 */
48struct rpmsg_ctrldev {
49 struct rpmsg_device *rpdev;
50 struct cdev cdev;
51 struct device dev;
52 struct mutex ctrl_lock;
53};
54
55static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp)
56{
57 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
58
59 get_device(dev: &ctrldev->dev);
60 filp->private_data = ctrldev;
61
62 return 0;
63}
64
65static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp)
66{
67 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
68
69 put_device(dev: &ctrldev->dev);
70
71 return 0;
72}
73
74static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd,
75 unsigned long arg)
76{
77 struct rpmsg_ctrldev *ctrldev = fp->private_data;
78 void __user *argp = (void __user *)arg;
79 struct rpmsg_endpoint_info eptinfo;
80 struct rpmsg_channel_info chinfo;
81 struct rpmsg_device *rpdev;
82 int ret = 0;
83
84 if (copy_from_user(to: &eptinfo, from: argp, n: sizeof(eptinfo)))
85 return -EFAULT;
86
87 memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE);
88 chinfo.name[RPMSG_NAME_SIZE - 1] = '\0';
89 chinfo.src = eptinfo.src;
90 chinfo.dst = eptinfo.dst;
91
92 mutex_lock(&ctrldev->ctrl_lock);
93 switch (cmd) {
94 case RPMSG_CREATE_EPT_IOCTL:
95 ret = rpmsg_chrdev_eptdev_create(rpdev: ctrldev->rpdev, parent: &ctrldev->dev, chinfo);
96 break;
97
98 case RPMSG_CREATE_DEV_IOCTL:
99 rpdev = rpmsg_create_channel(rpdev: ctrldev->rpdev, chinfo: &chinfo);
100 if (!rpdev) {
101 dev_err(&ctrldev->dev, "failed to create %s channel\n", chinfo.name);
102 ret = -ENXIO;
103 }
104 break;
105
106 case RPMSG_RELEASE_DEV_IOCTL:
107 ret = rpmsg_release_channel(rpdev: ctrldev->rpdev, chinfo: &chinfo);
108 if (ret)
109 dev_err(&ctrldev->dev, "failed to release %s channel (%d)\n",
110 chinfo.name, ret);
111 break;
112
113 default:
114 ret = -EINVAL;
115 }
116 mutex_unlock(lock: &ctrldev->ctrl_lock);
117
118 return ret;
119};
120
121static const struct file_operations rpmsg_ctrldev_fops = {
122 .owner = THIS_MODULE,
123 .open = rpmsg_ctrldev_open,
124 .release = rpmsg_ctrldev_release,
125 .unlocked_ioctl = rpmsg_ctrldev_ioctl,
126 .compat_ioctl = compat_ptr_ioctl,
127};
128
129static void rpmsg_ctrldev_release_device(struct device *dev)
130{
131 struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev);
132
133 ida_free(&rpmsg_ctrl_ida, id: dev->id);
134 ida_free(&rpmsg_minor_ida, MINOR(dev->devt));
135 kfree(objp: ctrldev);
136}
137
138static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev)
139{
140 struct rpmsg_ctrldev *ctrldev;
141 struct device *dev;
142 int ret;
143
144 ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL);
145 if (!ctrldev)
146 return -ENOMEM;
147
148 ctrldev->rpdev = rpdev;
149
150 dev = &ctrldev->dev;
151 device_initialize(dev);
152 dev->parent = &rpdev->dev;
153 dev->class = &rpmsg_class;
154
155 mutex_init(&ctrldev->ctrl_lock);
156 cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
157 ctrldev->cdev.owner = THIS_MODULE;
158
159 ret = ida_alloc_max(ida: &rpmsg_minor_ida, RPMSG_DEV_MAX - 1, GFP_KERNEL);
160 if (ret < 0)
161 goto free_ctrldev;
162 dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
163
164 ret = ida_alloc(ida: &rpmsg_ctrl_ida, GFP_KERNEL);
165 if (ret < 0)
166 goto free_minor_ida;
167 dev->id = ret;
168 dev_set_name(dev: &ctrldev->dev, name: "rpmsg_ctrl%d", ret);
169
170 ret = cdev_device_add(cdev: &ctrldev->cdev, dev: &ctrldev->dev);
171 if (ret)
172 goto free_ctrl_ida;
173
174 /* We can now rely on the release function for cleanup */
175 dev->release = rpmsg_ctrldev_release_device;
176
177 dev_set_drvdata(dev: &rpdev->dev, data: ctrldev);
178
179 return ret;
180
181free_ctrl_ida:
182 ida_free(&rpmsg_ctrl_ida, id: dev->id);
183free_minor_ida:
184 ida_free(&rpmsg_minor_ida, MINOR(dev->devt));
185free_ctrldev:
186 put_device(dev);
187 kfree(objp: ctrldev);
188
189 return ret;
190}
191
192static void rpmsg_ctrldev_remove(struct rpmsg_device *rpdev)
193{
194 struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(dev: &rpdev->dev);
195 int ret;
196
197 mutex_lock(&ctrldev->ctrl_lock);
198 /* Destroy all endpoints */
199 ret = device_for_each_child(parent: &ctrldev->dev, NULL, fn: rpmsg_chrdev_eptdev_destroy);
200 if (ret)
201 dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
202 mutex_unlock(lock: &ctrldev->ctrl_lock);
203
204 cdev_device_del(cdev: &ctrldev->cdev, dev: &ctrldev->dev);
205 put_device(dev: &ctrldev->dev);
206}
207
208static struct rpmsg_driver rpmsg_ctrldev_driver = {
209 .probe = rpmsg_ctrldev_probe,
210 .remove = rpmsg_ctrldev_remove,
211 .drv = {
212 .name = "rpmsg_ctrl",
213 },
214};
215
216static int rpmsg_ctrldev_init(void)
217{
218 int ret;
219
220 ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl");
221 if (ret < 0) {
222 pr_err("failed to allocate char dev region\n");
223 return ret;
224 }
225
226 ret = register_rpmsg_driver(&rpmsg_ctrldev_driver);
227 if (ret < 0) {
228 pr_err("failed to register rpmsg driver\n");
229 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
230 }
231
232 return ret;
233}
234postcore_initcall(rpmsg_ctrldev_init);
235
236static void rpmsg_ctrldev_exit(void)
237{
238 unregister_rpmsg_driver(drv: &rpmsg_ctrldev_driver);
239 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
240}
241module_exit(rpmsg_ctrldev_exit);
242
243MODULE_DESCRIPTION("rpmsg control interface");
244MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
245MODULE_LICENSE("GPL v2");
246

source code of linux/drivers/rpmsg/rpmsg_ctrl.c

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