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(&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(&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(&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 }; 120 121 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(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(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(&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; 180 181 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(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(&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 } 207 208 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(&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