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 cdev_device_del(&eptdev->cdev, &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_iter(struct kiocb *iocb, struct iov_iter *to)
172 struct file *filp = iocb->ki_filp;
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, iov_iter_count(to), skb->len);
209 if (copy_to_iter(skb->data, use, to) != use)
217 static ssize_t rpmsg_eptdev_write_iter(struct kiocb *iocb,
218 struct iov_iter *from)
220 struct file *filp = iocb->ki_filp;
221 struct rpmsg_eptdev *eptdev = filp->private_data;
222 size_t len = iov_iter_count(from);
226 kbuf = kzalloc(len, GFP_KERNEL);
230 if (!copy_from_iter_full(kbuf, len, from)) {
235 if (mutex_lock_interruptible(&eptdev->ept_lock)) {
245 if (filp->f_flags & O_NONBLOCK)
246 ret = rpmsg_trysend(eptdev->ept, kbuf, len);
248 ret = rpmsg_send(eptdev->ept, kbuf, len);
251 mutex_unlock(&eptdev->ept_lock);
255 return ret < 0 ? ret : len;
258 static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait)
260 struct rpmsg_eptdev *eptdev = filp->private_data;
266 poll_wait(filp, &eptdev->readq, wait);
268 if (!skb_queue_empty(&eptdev->queue))
269 mask |= EPOLLIN | EPOLLRDNORM;
271 mask |= rpmsg_poll(eptdev->ept, filp, wait);
276 static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
279 struct rpmsg_eptdev *eptdev = fp->private_data;
281 if (cmd != RPMSG_DESTROY_EPT_IOCTL)
284 return rpmsg_eptdev_destroy(&eptdev->dev, NULL);
287 static const struct file_operations rpmsg_eptdev_fops = {
288 .owner = THIS_MODULE,
289 .open = rpmsg_eptdev_open,
290 .release = rpmsg_eptdev_release,
291 .read_iter = rpmsg_eptdev_read_iter,
292 .write_iter = rpmsg_eptdev_write_iter,
293 .poll = rpmsg_eptdev_poll,
294 .unlocked_ioctl = rpmsg_eptdev_ioctl,
295 .compat_ioctl = rpmsg_eptdev_ioctl,
298 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
301 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
303 return sprintf(buf, "%s\n", eptdev->chinfo.name);
305 static DEVICE_ATTR_RO(name);
307 static ssize_t src_show(struct device *dev, struct device_attribute *attr,
310 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
312 return sprintf(buf, "%d\n", eptdev->chinfo.src);
314 static DEVICE_ATTR_RO(src);
316 static ssize_t dst_show(struct device *dev, struct device_attribute *attr,
319 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
321 return sprintf(buf, "%d\n", eptdev->chinfo.dst);
323 static DEVICE_ATTR_RO(dst);
325 static struct attribute *rpmsg_eptdev_attrs[] = {
331 ATTRIBUTE_GROUPS(rpmsg_eptdev);
333 static void rpmsg_eptdev_release_device(struct device *dev)
335 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
337 ida_simple_remove(&rpmsg_ept_ida, dev->id);
338 ida_simple_remove(&rpmsg_minor_ida, MINOR(eptdev->dev.devt));
342 static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev,
343 struct rpmsg_channel_info chinfo)
345 struct rpmsg_device *rpdev = ctrldev->rpdev;
346 struct rpmsg_eptdev *eptdev;
350 eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL);
355 eptdev->rpdev = rpdev;
356 eptdev->chinfo = chinfo;
358 mutex_init(&eptdev->ept_lock);
359 spin_lock_init(&eptdev->queue_lock);
360 skb_queue_head_init(&eptdev->queue);
361 init_waitqueue_head(&eptdev->readq);
363 device_initialize(dev);
364 dev->class = rpmsg_class;
365 dev->parent = &ctrldev->dev;
366 dev->groups = rpmsg_eptdev_groups;
367 dev_set_drvdata(dev, eptdev);
369 cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops);
370 eptdev->cdev.owner = THIS_MODULE;
372 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
375 dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
377 ret = ida_simple_get(&rpmsg_ept_ida, 0, 0, GFP_KERNEL);
381 dev_set_name(dev, "rpmsg%d", ret);
383 ret = cdev_device_add(&eptdev->cdev, &eptdev->dev);
387 /* We can now rely on the release function for cleanup */
388 dev->release = rpmsg_eptdev_release_device;
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));
461 static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
463 struct rpmsg_ctrldev *ctrldev;
467 ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL);
471 ctrldev->rpdev = rpdev;
474 device_initialize(dev);
475 dev->parent = &rpdev->dev;
476 dev->class = rpmsg_class;
478 cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
479 ctrldev->cdev.owner = THIS_MODULE;
481 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
484 dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
486 ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL);
490 dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret);
492 ret = cdev_device_add(&ctrldev->cdev, &ctrldev->dev);
496 /* We can now rely on the release function for cleanup */
497 dev->release = rpmsg_ctrldev_release_device;
499 dev_set_drvdata(&rpdev->dev, ctrldev);
504 ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
506 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
514 static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
516 struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev);
519 /* Destroy all endpoints */
520 ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_eptdev_destroy);
522 dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
524 cdev_device_del(&ctrldev->cdev, &ctrldev->dev);
525 put_device(&ctrldev->dev);
528 static struct rpmsg_driver rpmsg_chrdev_driver = {
529 .probe = rpmsg_chrdev_probe,
530 .remove = rpmsg_chrdev_remove,
532 .name = "rpmsg_chrdev",
536 static int rpmsg_char_init(void)
540 ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg");
542 pr_err("rpmsg: failed to allocate char dev region\n");
546 rpmsg_class = class_create(THIS_MODULE, "rpmsg");
547 if (IS_ERR(rpmsg_class)) {
548 pr_err("failed to create rpmsg class\n");
549 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
550 return PTR_ERR(rpmsg_class);
553 ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
555 pr_err("rpmsgchr: failed to register rpmsg driver\n");
556 class_destroy(rpmsg_class);
557 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
562 postcore_initcall(rpmsg_char_init);
564 static void rpmsg_chrdev_exit(void)
566 unregister_rpmsg_driver(&rpmsg_chrdev_driver);
567 class_destroy(rpmsg_class);
568 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
570 module_exit(rpmsg_chrdev_exit);
572 MODULE_ALIAS("rpmsg:rpmsg_chrdev");
573 MODULE_LICENSE("GPL v2");