rpmsg_ctrl.c 5.8 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243
  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 <[email protected]>
  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. #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14. #include <linux/cdev.h>
  15. #include <linux/device.h>
  16. #include <linux/fs.h>
  17. #include <linux/idr.h>
  18. #include <linux/kernel.h>
  19. #include <linux/module.h>
  20. #include <linux/rpmsg.h>
  21. #include <linux/skbuff.h>
  22. #include <linux/slab.h>
  23. #include <linux/uaccess.h>
  24. #include <uapi/linux/rpmsg.h>
  25. #include "rpmsg_char.h"
  26. #include "rpmsg_internal.h"
  27. #define RPMSG_DEV_MAX (MINORMASK + 1)
  28. static dev_t rpmsg_major;
  29. static DEFINE_IDA(rpmsg_ctrl_ida);
  30. static DEFINE_IDA(rpmsg_minor_ida);
  31. #define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev)
  32. #define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev)
  33. /**
  34. * struct rpmsg_ctrldev - control device for instantiating endpoint devices
  35. * @rpdev: underlaying rpmsg device
  36. * @cdev: cdev for the ctrl device
  37. * @dev: device for the ctrl device
  38. * @ctrl_lock: serialize the ioctrls.
  39. */
  40. struct rpmsg_ctrldev {
  41. struct rpmsg_device *rpdev;
  42. struct cdev cdev;
  43. struct device dev;
  44. struct mutex ctrl_lock;
  45. };
  46. static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp)
  47. {
  48. struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
  49. get_device(&ctrldev->dev);
  50. filp->private_data = ctrldev;
  51. return 0;
  52. }
  53. static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp)
  54. {
  55. struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
  56. put_device(&ctrldev->dev);
  57. return 0;
  58. }
  59. static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd,
  60. unsigned long arg)
  61. {
  62. struct rpmsg_ctrldev *ctrldev = fp->private_data;
  63. void __user *argp = (void __user *)arg;
  64. struct rpmsg_endpoint_info eptinfo;
  65. struct rpmsg_channel_info chinfo;
  66. struct rpmsg_device *rpdev;
  67. int ret = 0;
  68. if (copy_from_user(&eptinfo, argp, sizeof(eptinfo)))
  69. return -EFAULT;
  70. memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE);
  71. chinfo.name[RPMSG_NAME_SIZE - 1] = '\0';
  72. chinfo.src = eptinfo.src;
  73. chinfo.dst = eptinfo.dst;
  74. mutex_lock(&ctrldev->ctrl_lock);
  75. switch (cmd) {
  76. case RPMSG_CREATE_EPT_IOCTL:
  77. ret = rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo);
  78. break;
  79. case RPMSG_CREATE_DEV_IOCTL:
  80. rpdev = rpmsg_create_channel(ctrldev->rpdev, &chinfo);
  81. if (!rpdev) {
  82. dev_err(&ctrldev->dev, "failed to create %s channel\n", chinfo.name);
  83. ret = -ENXIO;
  84. }
  85. break;
  86. case RPMSG_RELEASE_DEV_IOCTL:
  87. ret = rpmsg_release_channel(ctrldev->rpdev, &chinfo);
  88. if (ret)
  89. dev_err(&ctrldev->dev, "failed to release %s channel (%d)\n",
  90. chinfo.name, ret);
  91. break;
  92. default:
  93. ret = -EINVAL;
  94. }
  95. mutex_unlock(&ctrldev->ctrl_lock);
  96. return ret;
  97. };
  98. static const struct file_operations rpmsg_ctrldev_fops = {
  99. .owner = THIS_MODULE,
  100. .open = rpmsg_ctrldev_open,
  101. .release = rpmsg_ctrldev_release,
  102. .unlocked_ioctl = rpmsg_ctrldev_ioctl,
  103. .compat_ioctl = compat_ptr_ioctl,
  104. };
  105. static void rpmsg_ctrldev_release_device(struct device *dev)
  106. {
  107. struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev);
  108. ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
  109. ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
  110. kfree(ctrldev);
  111. }
  112. static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev)
  113. {
  114. struct rpmsg_ctrldev *ctrldev;
  115. struct device *dev;
  116. int ret;
  117. ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL);
  118. if (!ctrldev)
  119. return -ENOMEM;
  120. ctrldev->rpdev = rpdev;
  121. dev = &ctrldev->dev;
  122. device_initialize(dev);
  123. dev->parent = &rpdev->dev;
  124. dev->class = rpmsg_class;
  125. mutex_init(&ctrldev->ctrl_lock);
  126. cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
  127. ctrldev->cdev.owner = THIS_MODULE;
  128. ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
  129. if (ret < 0)
  130. goto free_ctrldev;
  131. dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
  132. ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL);
  133. if (ret < 0)
  134. goto free_minor_ida;
  135. dev->id = ret;
  136. dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret);
  137. ret = cdev_device_add(&ctrldev->cdev, &ctrldev->dev);
  138. if (ret)
  139. goto free_ctrl_ida;
  140. /* We can now rely on the release function for cleanup */
  141. dev->release = rpmsg_ctrldev_release_device;
  142. dev_set_drvdata(&rpdev->dev, ctrldev);
  143. return ret;
  144. free_ctrl_ida:
  145. ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
  146. free_minor_ida:
  147. ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
  148. free_ctrldev:
  149. put_device(dev);
  150. kfree(ctrldev);
  151. return ret;
  152. }
  153. static void rpmsg_ctrldev_remove(struct rpmsg_device *rpdev)
  154. {
  155. struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev);
  156. int ret;
  157. /* Destroy all endpoints */
  158. ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_chrdev_eptdev_destroy);
  159. if (ret)
  160. dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
  161. cdev_device_del(&ctrldev->cdev, &ctrldev->dev);
  162. put_device(&ctrldev->dev);
  163. }
  164. static struct rpmsg_driver rpmsg_ctrldev_driver = {
  165. .probe = rpmsg_ctrldev_probe,
  166. .remove = rpmsg_ctrldev_remove,
  167. .drv = {
  168. .name = "rpmsg_ctrl",
  169. },
  170. };
  171. static int rpmsg_ctrldev_init(void)
  172. {
  173. int ret;
  174. ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl");
  175. if (ret < 0) {
  176. pr_err("failed to allocate char dev region\n");
  177. return ret;
  178. }
  179. ret = register_rpmsg_driver(&rpmsg_ctrldev_driver);
  180. if (ret < 0) {
  181. pr_err("failed to register rpmsg driver\n");
  182. unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
  183. }
  184. return ret;
  185. }
  186. postcore_initcall(rpmsg_ctrldev_init);
  187. static void rpmsg_ctrldev_exit(void)
  188. {
  189. unregister_rpmsg_driver(&rpmsg_ctrldev_driver);
  190. unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
  191. }
  192. module_exit(rpmsg_ctrldev_exit);
  193. MODULE_DESCRIPTION("rpmsg control interface");
  194. MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
  195. MODULE_LICENSE("GPL v2");