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 | |
33 | static dev_t rpmsg_major; |
34 | |
35 | static DEFINE_IDA(rpmsg_ctrl_ida); |
36 | static 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 | */ |
48 | struct rpmsg_ctrldev { |
49 | struct rpmsg_device *rpdev; |
50 | struct cdev cdev; |
51 | struct device dev; |
52 | struct mutex ctrl_lock; |
53 | }; |
54 | |
55 | static 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 | |
65 | static 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 | |
74 | static 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 | |
121 | static 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 | |
129 | static void rpmsg_ctrldev_release_device(struct device *dev) |
130 | { |
131 | struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev); |
132 | |
133 | ida_simple_remove(&rpmsg_ctrl_ida, dev->id); |
134 | ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); |
135 | kfree(objp: ctrldev); |
136 | } |
137 | |
138 | static 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(size: 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_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); |
160 | if (ret < 0) |
161 | goto free_ctrldev; |
162 | dev->devt = MKDEV(MAJOR(rpmsg_major), ret); |
163 | |
164 | ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, 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 | |
181 | free_ctrl_ida: |
182 | ida_simple_remove(&rpmsg_ctrl_ida, dev->id); |
183 | free_minor_ida: |
184 | ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); |
185 | free_ctrldev: |
186 | put_device(dev); |
187 | kfree(objp: ctrldev); |
188 | |
189 | return ret; |
190 | } |
191 | |
192 | static 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(dev: &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 | |
208 | static 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 | |
216 | static 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 | } |
234 | postcore_initcall(rpmsg_ctrldev_init); |
235 | |
236 | static void rpmsg_ctrldev_exit(void) |
237 | { |
238 | unregister_rpmsg_driver(drv: &rpmsg_ctrldev_driver); |
239 | unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); |
240 | } |
241 | module_exit(rpmsg_ctrldev_exit); |
242 | |
243 | MODULE_DESCRIPTION("rpmsg control interface" ); |
244 | MODULE_ALIAS("rpmsg:" KBUILD_MODNAME); |
245 | MODULE_LICENSE("GPL v2" ); |
246 | |