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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (C) 2022, STMicroelectronics4 * Copyright (c) 2016, Linaro Ltd.5 * Copyright (c) 2012, Michal Simek <monstr@monstr.eu>6 * Copyright (c) 2012, PetaLogix7 * 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 turn11 * was based on TI & Google OMX rpmsg driver.12 */13 14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt15 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 devices43 * @rpdev: underlaying rpmsg device44 * @cdev: cdev for the ctrl device45 * @dev: device for the ctrl device46 * @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(&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(&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(&eptinfo, argp, 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(ctrldev->rpdev, &ctrldev->dev, chinfo);96 break;97 98 case RPMSG_CREATE_DEV_IOCTL:99 rpdev = rpmsg_create_channel(ctrldev->rpdev, &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(ctrldev->rpdev, &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(&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, dev->id);134 ida_free(&rpmsg_minor_ida, MINOR(dev->devt));135 kfree(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(&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(&rpmsg_ctrl_ida, GFP_KERNEL);165 if (ret < 0)166 goto free_minor_ida;167 dev->id = ret;168 dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret);169 170 ret = cdev_device_add(&ctrldev->cdev, &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(&rpdev->dev, ctrldev);178 179 return ret;180 181free_ctrl_ida:182 ida_free(&rpmsg_ctrl_ida, dev->id);183free_minor_ida:184 ida_free(&rpmsg_minor_ida, MINOR(dev->devt));185free_ctrldev:186 put_device(dev);187 kfree(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(&rpdev->dev);195 int ret;196 197 mutex_lock(&ctrldev->ctrl_lock);198 /* Destroy all endpoints */199 ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_chrdev_eptdev_destroy);200 if (ret)201 dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);202 mutex_unlock(&ctrldev->ctrl_lock);203 204 cdev_device_del(&ctrldev->cdev, &ctrldev->dev);205 put_device(&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(&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