1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2016, Linaro Ltd.
4 * Copyright (c) 2012, Michal Simek <monstr@monstr.eu>
5 * Copyright (c) 2012, PetaLogix
6 * Copyright (c) 2011, Texas Instruments, Inc.
7 * Copyright (c) 2011, Google, Inc.
9 * Based on rpmsg performance statistics driver by Michal Simek, which in turn
10 * was based on TI & Google OMX rpmsg driver.
12 #include <linux/cdev.h>
13 #include <linux/device.h>
15 #include <linux/idr.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/poll.h>
19 #include <linux/rpmsg.h>
20 #include <linux/skbuff.h>
21 #include <linux/slab.h>
22 #include <linux/uaccess.h>
23 #include <uapi/linux/rpmsg.h>
25 #include "rpmsg_internal.h"
27 #define RPMSG_DEV_MAX (MINORMASK + 1)
29 static dev_t rpmsg_major;
30 static struct class *rpmsg_class;
32 static DEFINE_IDA(rpmsg_ctrl_ida);
33 static DEFINE_IDA(rpmsg_ept_ida);
34 static DEFINE_IDA(rpmsg_minor_ida);
36 #define dev_to_eptdev(dev) container_of(dev, struct rpmsg_eptdev, dev)
37 #define cdev_to_eptdev(i_cdev) container_of(i_cdev, struct rpmsg_eptdev, cdev)
39 #define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev)
40 #define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev)
43 * struct rpmsg_ctrldev - control device for instantiating endpoint devices
44 * @rpdev: underlaying rpmsg device
45 * @cdev: cdev for the ctrl device
46 * @dev: device for the ctrl device
48 struct rpmsg_ctrldev {
49 struct rpmsg_device *rpdev;
55 * struct rpmsg_eptdev - endpoint device context
56 * @dev: endpoint device
57 * @cdev: cdev for the endpoint device
58 * @rpdev: underlaying rpmsg device
59 * @chinfo: info used to open the endpoint
60 * @ept_lock: synchronization of @ept modifications
61 * @ept: rpmsg endpoint reference, when open
62 * @queue_lock: synchronization of @queue operations
63 * @queue: incoming message queue
64 * @readq: wait object for incoming queue
70 struct rpmsg_device *rpdev;
71 struct rpmsg_channel_info chinfo;
73 struct mutex ept_lock;
74 struct rpmsg_endpoint *ept;
76 spinlock_t queue_lock;
77 struct sk_buff_head queue;
78 wait_queue_head_t readq;
81 static int rpmsg_eptdev_destroy(struct device *dev, void *data)
83 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
85 mutex_lock(&eptdev->ept_lock);
87 rpmsg_destroy_ept(eptdev->ept);
90 mutex_unlock(&eptdev->ept_lock);
92 /* wake up any blocked readers */
93 wake_up_interruptible(&eptdev->readq);
95 device_del(&eptdev->dev);
96 put_device(&eptdev->dev);
101 static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len,
102 void *priv, u32 addr)
104 struct rpmsg_eptdev *eptdev = priv;
107 skb = alloc_skb(len, GFP_ATOMIC);
111 skb_put_data(skb, buf, len);
113 spin_lock(&eptdev->queue_lock);
114 skb_queue_tail(&eptdev->queue, skb);
115 spin_unlock(&eptdev->queue_lock);
117 /* wake up any blocking processes, waiting for new data */
118 wake_up_interruptible(&eptdev->readq);
123 static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
125 struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
126 struct rpmsg_endpoint *ept;
127 struct rpmsg_device *rpdev = eptdev->rpdev;
128 struct device *dev = &eptdev->dev;
132 ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo);
134 dev_err(dev, "failed to open %s\n", eptdev->chinfo.name);
140 filp->private_data = eptdev;
145 static int rpmsg_eptdev_release(struct inode *inode, struct file *filp)
147 struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
148 struct device *dev = &eptdev->dev;
151 /* Close the endpoint, if it's not already destroyed by the parent */
152 mutex_lock(&eptdev->ept_lock);
154 rpmsg_destroy_ept(eptdev->ept);
157 mutex_unlock(&eptdev->ept_lock);
159 /* Discard all SKBs */
160 while (!skb_queue_empty(&eptdev->queue)) {
161 skb = skb_dequeue(&eptdev->queue);
170 static ssize_t rpmsg_eptdev_read(struct file *filp, char __user *buf,
171 size_t len, loff_t *f_pos)
173 struct rpmsg_eptdev *eptdev = filp->private_data;
181 spin_lock_irqsave(&eptdev->queue_lock, flags);
183 /* Wait for data in the queue */
184 if (skb_queue_empty(&eptdev->queue)) {
185 spin_unlock_irqrestore(&eptdev->queue_lock, flags);
187 if (filp->f_flags & O_NONBLOCK)
190 /* Wait until we get data or the endpoint goes away */
191 if (wait_event_interruptible(eptdev->readq,
192 !skb_queue_empty(&eptdev->queue) ||
196 /* We lost the endpoint while waiting */
200 spin_lock_irqsave(&eptdev->queue_lock, flags);
203 skb = skb_dequeue(&eptdev->queue);
204 spin_unlock_irqrestore(&eptdev->queue_lock, flags);
208 use = min_t(size_t, len, skb->len);
209 if (copy_to_user(buf, skb->data, use))
217 static ssize_t rpmsg_eptdev_write(struct file *filp, const char __user *buf,
218 size_t len, loff_t *f_pos)
220 struct rpmsg_eptdev *eptdev = filp->private_data;
224 kbuf = memdup_user(buf, len);
226 return PTR_ERR(kbuf);
228 if (mutex_lock_interruptible(&eptdev->ept_lock)) {
238 if (filp->f_flags & O_NONBLOCK)
239 ret = rpmsg_trysend(eptdev->ept, kbuf, len);
241 ret = rpmsg_send(eptdev->ept, kbuf, len);
244 mutex_unlock(&eptdev->ept_lock);
248 return ret < 0 ? ret : len;
251 static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait)
253 struct rpmsg_eptdev *eptdev = filp->private_data;
259 poll_wait(filp, &eptdev->readq, wait);
261 if (!skb_queue_empty(&eptdev->queue))
262 mask |= EPOLLIN | EPOLLRDNORM;
264 mask |= rpmsg_poll(eptdev->ept, filp, wait);
269 static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
272 struct rpmsg_eptdev *eptdev = fp->private_data;
274 if (cmd != RPMSG_DESTROY_EPT_IOCTL)
277 return rpmsg_eptdev_destroy(&eptdev->dev, NULL);
280 static const struct file_operations rpmsg_eptdev_fops = {
281 .owner = THIS_MODULE,
282 .open = rpmsg_eptdev_open,
283 .release = rpmsg_eptdev_release,
284 .read = rpmsg_eptdev_read,
285 .write = rpmsg_eptdev_write,
286 .poll = rpmsg_eptdev_poll,
287 .unlocked_ioctl = rpmsg_eptdev_ioctl,
288 .compat_ioctl = rpmsg_eptdev_ioctl,
291 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
294 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
296 return sprintf(buf, "%s\n", eptdev->chinfo.name);
298 static DEVICE_ATTR_RO(name);
300 static ssize_t src_show(struct device *dev, struct device_attribute *attr,
303 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
305 return sprintf(buf, "%d\n", eptdev->chinfo.src);
307 static DEVICE_ATTR_RO(src);
309 static ssize_t dst_show(struct device *dev, struct device_attribute *attr,
312 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
314 return sprintf(buf, "%d\n", eptdev->chinfo.dst);
316 static DEVICE_ATTR_RO(dst);
318 static struct attribute *rpmsg_eptdev_attrs[] = {
324 ATTRIBUTE_GROUPS(rpmsg_eptdev);
326 static void rpmsg_eptdev_release_device(struct device *dev)
328 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
330 ida_simple_remove(&rpmsg_ept_ida, dev->id);
331 ida_simple_remove(&rpmsg_minor_ida, MINOR(eptdev->dev.devt));
332 cdev_del(&eptdev->cdev);
336 static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev,
337 struct rpmsg_channel_info chinfo)
339 struct rpmsg_device *rpdev = ctrldev->rpdev;
340 struct rpmsg_eptdev *eptdev;
344 eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL);
349 eptdev->rpdev = rpdev;
350 eptdev->chinfo = chinfo;
352 mutex_init(&eptdev->ept_lock);
353 spin_lock_init(&eptdev->queue_lock);
354 skb_queue_head_init(&eptdev->queue);
355 init_waitqueue_head(&eptdev->readq);
357 device_initialize(dev);
358 dev->class = rpmsg_class;
359 dev->parent = &ctrldev->dev;
360 dev->groups = rpmsg_eptdev_groups;
361 dev_set_drvdata(dev, eptdev);
363 cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops);
364 eptdev->cdev.owner = THIS_MODULE;
366 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
369 dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
371 ret = ida_simple_get(&rpmsg_ept_ida, 0, 0, GFP_KERNEL);
375 dev_set_name(dev, "rpmsg%d", ret);
377 ret = cdev_add(&eptdev->cdev, dev->devt, 1);
381 /* We can now rely on the release function for cleanup */
382 dev->release = rpmsg_eptdev_release_device;
384 ret = device_add(dev);
386 dev_err(dev, "device_add failed: %d\n", ret);
393 ida_simple_remove(&rpmsg_ept_ida, dev->id);
395 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
403 static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp)
405 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
407 get_device(&ctrldev->dev);
408 filp->private_data = ctrldev;
413 static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp)
415 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
417 put_device(&ctrldev->dev);
422 static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd,
425 struct rpmsg_ctrldev *ctrldev = fp->private_data;
426 void __user *argp = (void __user *)arg;
427 struct rpmsg_endpoint_info eptinfo;
428 struct rpmsg_channel_info chinfo;
430 if (cmd != RPMSG_CREATE_EPT_IOCTL)
433 if (copy_from_user(&eptinfo, argp, sizeof(eptinfo)))
436 memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE);
437 chinfo.name[RPMSG_NAME_SIZE-1] = '\0';
438 chinfo.src = eptinfo.src;
439 chinfo.dst = eptinfo.dst;
441 return rpmsg_eptdev_create(ctrldev, chinfo);
444 static const struct file_operations rpmsg_ctrldev_fops = {
445 .owner = THIS_MODULE,
446 .open = rpmsg_ctrldev_open,
447 .release = rpmsg_ctrldev_release,
448 .unlocked_ioctl = rpmsg_ctrldev_ioctl,
449 .compat_ioctl = rpmsg_ctrldev_ioctl,
452 static void rpmsg_ctrldev_release_device(struct device *dev)
454 struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev);
456 ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
457 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
458 cdev_del(&ctrldev->cdev);
462 static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
464 struct rpmsg_ctrldev *ctrldev;
468 ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL);
472 ctrldev->rpdev = rpdev;
475 device_initialize(dev);
476 dev->parent = &rpdev->dev;
477 dev->class = rpmsg_class;
479 cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
480 ctrldev->cdev.owner = THIS_MODULE;
482 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
485 dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
487 ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL);
491 dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret);
493 ret = cdev_add(&ctrldev->cdev, dev->devt, 1);
497 /* We can now rely on the release function for cleanup */
498 dev->release = rpmsg_ctrldev_release_device;
500 ret = device_add(dev);
502 dev_err(&rpdev->dev, "device_add failed: %d\n", ret);
506 dev_set_drvdata(&rpdev->dev, ctrldev);
511 ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
513 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
521 static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
523 struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev);
526 /* Destroy all endpoints */
527 ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_eptdev_destroy);
529 dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
531 device_del(&ctrldev->dev);
532 put_device(&ctrldev->dev);
535 static struct rpmsg_driver rpmsg_chrdev_driver = {
536 .probe = rpmsg_chrdev_probe,
537 .remove = rpmsg_chrdev_remove,
539 .name = "rpmsg_chrdev",
543 static int rpmsg_char_init(void)
547 ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg");
549 pr_err("rpmsg: failed to allocate char dev region\n");
553 rpmsg_class = class_create(THIS_MODULE, "rpmsg");
554 if (IS_ERR(rpmsg_class)) {
555 pr_err("failed to create rpmsg class\n");
556 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
557 return PTR_ERR(rpmsg_class);
560 ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
562 pr_err("rpmsgchr: failed to register rpmsg driver\n");
563 class_destroy(rpmsg_class);
564 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
569 postcore_initcall(rpmsg_char_init);
571 static void rpmsg_chrdev_exit(void)
573 unregister_rpmsg_driver(&rpmsg_chrdev_driver);
574 class_destroy(rpmsg_class);
575 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
577 module_exit(rpmsg_chrdev_exit);
579 MODULE_ALIAS("rpmsg:rpmsg_chrdev");
580 MODULE_LICENSE("GPL v2");