[linux-block.git] / drivers / rpmsg / rpmsg_char.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2022, STMicroelectronics
 * Copyright (c) 2016, Linaro Ltd.
 * Copyright (c) 2012, Michal Simek <monstr@monstr.eu>
 * Copyright (c) 2012, PetaLogix
 * Copyright (c) 2011, Texas Instruments, Inc.
 * Copyright (c) 2011, Google, Inc.
 *
 * Based on rpmsg performance statistics driver by Michal Simek, which in turn
 * was based on TI & Google OMX rpmsg driver.
 */

#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/rpmsg.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <uapi/linux/rpmsg.h>

#include "rpmsg_char.h"
#include "rpmsg_internal.h"

#define RPMSG_DEV_MAX	(MINORMASK + 1)

static dev_t rpmsg_major;

static DEFINE_IDA(rpmsg_ept_ida);
static DEFINE_IDA(rpmsg_minor_ida);

#define dev_to_eptdev(dev) container_of(dev, struct rpmsg_eptdev, dev)
#define cdev_to_eptdev(i_cdev) container_of(i_cdev, struct rpmsg_eptdev, cdev)

/**
 * struct rpmsg_eptdev - endpoint device context
 * @dev:	endpoint device
 * @cdev:	cdev for the endpoint device
 * @rpdev:	underlaying rpmsg device
 * @chinfo:	info used to open the endpoint
 * @ept_lock:	synchronization of @ept modifications
 * @ept:	rpmsg endpoint reference, when open
 * @queue_lock:	synchronization of @queue operations
 * @queue:	incoming message queue
 * @readq:	wait object for incoming queue
 * @default_ept: set to channel default endpoint if the default endpoint should be re-used
 *              on device open to prevent endpoint address update.
 */
struct rpmsg_eptdev {
	struct device dev;
	struct cdev cdev;

	struct rpmsg_device *rpdev;
	struct rpmsg_channel_info chinfo;

	struct mutex ept_lock;
	struct rpmsg_endpoint *ept;
	struct rpmsg_endpoint *default_ept;

	spinlock_t queue_lock;
	struct sk_buff_head queue;
	wait_queue_head_t readq;

};

int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data)
{
	struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);

	mutex_lock(&eptdev->ept_lock);
	eptdev->rpdev = NULL;
	if (eptdev->ept) {
		/* The default endpoint is released by the rpmsg core */
		if (!eptdev->default_ept)
			rpmsg_destroy_ept(eptdev->ept);
		eptdev->ept = NULL;
	}
	mutex_unlock(&eptdev->ept_lock);

	/* wake up any blocked readers */
	wake_up_interruptible(&eptdev->readq);

	cdev_device_del(&eptdev->cdev, &eptdev->dev);
	put_device(&eptdev->dev);

	return 0;
}
EXPORT_SYMBOL(rpmsg_chrdev_eptdev_destroy);

static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len,
			void *priv, u32 addr)
{
	struct rpmsg_eptdev *eptdev = priv;
	struct sk_buff *skb;

	skb = alloc_skb(len, GFP_ATOMIC);
	if (!skb)
		return -ENOMEM;

	skb_put_data(skb, buf, len);

	spin_lock(&eptdev->queue_lock);
	skb_queue_tail(&eptdev->queue, skb);
	spin_unlock(&eptdev->queue_lock);

	/* wake up any blocking processes, waiting for new data */
	wake_up_interruptible(&eptdev->readq);

	return 0;
}

static int rpmsg_eptdev_open(struct inode *inode, struct file *filp)
{
	struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
	struct rpmsg_endpoint *ept;
	struct rpmsg_device *rpdev = eptdev->rpdev;
	struct device *dev = &eptdev->dev;

	mutex_lock(&eptdev->ept_lock);
	if (eptdev->ept) {
		mutex_unlock(&eptdev->ept_lock);
		return -EBUSY;
	}

	if (!eptdev->rpdev) {
		mutex_unlock(&eptdev->ept_lock);
		return -ENETRESET;
	}

	get_device(dev);

	/*
	 * If the default_ept is set, the rpmsg device default endpoint is used.
	 * Else a new endpoint is created on open that will be destroyed on release.
	 */
	if (eptdev->default_ept)
		ept = eptdev->default_ept;
	else
		ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo);

	if (!ept) {
		dev_err(dev, "failed to open %s\n", eptdev->chinfo.name);
		put_device(dev);
		mutex_unlock(&eptdev->ept_lock);
		return -EINVAL;
	}

	eptdev->ept = ept;
	filp->private_data = eptdev;
	mutex_unlock(&eptdev->ept_lock);

	return 0;
}

static int rpmsg_eptdev_release(struct inode *inode, struct file *filp)
{
	struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
	struct device *dev = &eptdev->dev;

	/* Close the endpoint, if it's not already destroyed by the parent */
	mutex_lock(&eptdev->ept_lock);
	if (eptdev->ept) {
		if (!eptdev->default_ept)
			rpmsg_destroy_ept(eptdev->ept);
		eptdev->ept = NULL;
	}
	mutex_unlock(&eptdev->ept_lock);

	/* Discard all SKBs */
	skb_queue_purge(&eptdev->queue);

	put_device(dev);

	return 0;
}

static ssize_t rpmsg_eptdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
	struct file *filp = iocb->ki_filp;
	struct rpmsg_eptdev *eptdev = filp->private_data;
	unsigned long flags;
	struct sk_buff *skb;
	int use;

	if (!eptdev->ept)
		return -EPIPE;

	spin_lock_irqsave(&eptdev->queue_lock, flags);

	/* Wait for data in the queue */
	if (skb_queue_empty(&eptdev->queue)) {
		spin_unlock_irqrestore(&eptdev->queue_lock, flags);

		if (filp->f_flags & O_NONBLOCK)
			return -EAGAIN;

		/* Wait until we get data or the endpoint goes away */
		if (wait_event_interruptible(eptdev->readq,
					     !skb_queue_empty(&eptdev->queue) ||
					     !eptdev->ept))
			return -ERESTARTSYS;

		/* We lost the endpoint while waiting */
		if (!eptdev->ept)
			return -EPIPE;

		spin_lock_irqsave(&eptdev->queue_lock, flags);
	}

	skb = skb_dequeue(&eptdev->queue);
	spin_unlock_irqrestore(&eptdev->queue_lock, flags);
	if (!skb)
		return -EFAULT;

	use = min_t(size_t, iov_iter_count(to), skb->len);
	if (copy_to_iter(skb->data, use, to) != use)
		use = -EFAULT;

	kfree_skb(skb);

	return use;
}

static ssize_t rpmsg_eptdev_write_iter(struct kiocb *iocb,
				       struct iov_iter *from)
{
	struct file *filp = iocb->ki_filp;
	struct rpmsg_eptdev *eptdev = filp->private_data;
	size_t len = iov_iter_count(from);
	void *kbuf;
	int ret;

	kbuf = kzalloc(len, GFP_KERNEL);
	if (!kbuf)
		return -ENOMEM;

	if (!copy_from_iter_full(kbuf, len, from)) {
		ret = -EFAULT;
		goto free_kbuf;
	}

	if (mutex_lock_interruptible(&eptdev->ept_lock)) {
		ret = -ERESTARTSYS;
		goto free_kbuf;
	}

	if (!eptdev->ept) {
		ret = -EPIPE;
		goto unlock_eptdev;
	}

	if (filp->f_flags & O_NONBLOCK) {
		ret = rpmsg_trysendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst);
		if (ret == -ENOMEM)
			ret = -EAGAIN;
	} else {
		ret = rpmsg_sendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst);
	}

unlock_eptdev:
	mutex_unlock(&eptdev->ept_lock);

free_kbuf:
	kfree(kbuf);
	return ret < 0 ? ret : len;
}

static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait)
{
	struct rpmsg_eptdev *eptdev = filp->private_data;
	__poll_t mask = 0;

	if (!eptdev->ept)
		return EPOLLERR;

	poll_wait(filp, &eptdev->readq, wait);

	if (!skb_queue_empty(&eptdev->queue))
		mask |= EPOLLIN | EPOLLRDNORM;

	mutex_lock(&eptdev->ept_lock);
	mask |= rpmsg_poll(eptdev->ept, filp, wait);
	mutex_unlock(&eptdev->ept_lock);

	return mask;
}

static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
			       unsigned long arg)
{
	struct rpmsg_eptdev *eptdev = fp->private_data;

	if (cmd != RPMSG_DESTROY_EPT_IOCTL)
		return -EINVAL;

	/* Don't allow to destroy a default endpoint. */
	if (eptdev->default_ept)
		return -EINVAL;

	return rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
}

static const struct file_operations rpmsg_eptdev_fops = {
	.owner = THIS_MODULE,
	.open = rpmsg_eptdev_open,
	.release = rpmsg_eptdev_release,
	.read_iter = rpmsg_eptdev_read_iter,
	.write_iter = rpmsg_eptdev_write_iter,
	.poll = rpmsg_eptdev_poll,
	.unlocked_ioctl = rpmsg_eptdev_ioctl,
	.compat_ioctl = compat_ptr_ioctl,
};

static ssize_t name_show(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);

	return sprintf(buf, "%s\n", eptdev->chinfo.name);
}
static DEVICE_ATTR_RO(name);

static ssize_t src_show(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", eptdev->chinfo.src);
}
static DEVICE_ATTR_RO(src);

static ssize_t dst_show(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", eptdev->chinfo.dst);
}
static DEVICE_ATTR_RO(dst);

static struct attribute *rpmsg_eptdev_attrs[] = {
	&dev_attr_name.attr,
	&dev_attr_src.attr,
	&dev_attr_dst.attr,
	NULL
};
ATTRIBUTE_GROUPS(rpmsg_eptdev);

static void rpmsg_eptdev_release_device(struct device *dev)
{
	struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);

	ida_simple_remove(&rpmsg_ept_ida, dev->id);
	ida_simple_remove(&rpmsg_minor_ida, MINOR(eptdev->dev.devt));
	kfree(eptdev);
}

static struct rpmsg_eptdev *rpmsg_chrdev_eptdev_alloc(struct rpmsg_device *rpdev,
						      struct device *parent)
{
	struct rpmsg_eptdev *eptdev;
	struct device *dev;

	eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL);
	if (!eptdev)
		return ERR_PTR(-ENOMEM);

	dev = &eptdev->dev;
	eptdev->rpdev = rpdev;

	mutex_init(&eptdev->ept_lock);
	spin_lock_init(&eptdev->queue_lock);
	skb_queue_head_init(&eptdev->queue);
	init_waitqueue_head(&eptdev->readq);

	device_initialize(dev);
	dev->class = rpmsg_class;
	dev->parent = parent;
	dev->groups = rpmsg_eptdev_groups;
	dev_set_drvdata(dev, eptdev);

	cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops);
	eptdev->cdev.owner = THIS_MODULE;

	return eptdev;
}

static int rpmsg_chrdev_eptdev_add(struct rpmsg_eptdev *eptdev, struct rpmsg_channel_info chinfo)
{
	struct device *dev = &eptdev->dev;
	int ret;

	eptdev->chinfo = chinfo;

	ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
	if (ret < 0)
		goto free_eptdev;
	dev->devt = MKDEV(MAJOR(rpmsg_major), ret);

	ret = ida_simple_get(&rpmsg_ept_ida, 0, 0, GFP_KERNEL);
	if (ret < 0)
		goto free_minor_ida;
	dev->id = ret;
	dev_set_name(dev, "rpmsg%d", ret);

	ret = cdev_device_add(&eptdev->cdev, &eptdev->dev);
	if (ret)
		goto free_ept_ida;

	/* We can now rely on the release function for cleanup */
	dev->release = rpmsg_eptdev_release_device;

	return ret;

free_ept_ida:
	ida_simple_remove(&rpmsg_ept_ida, dev->id);
free_minor_ida:
	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
free_eptdev:
	put_device(dev);
	kfree(eptdev);

	return ret;
}

int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent,
			       struct rpmsg_channel_info chinfo)
{
	struct rpmsg_eptdev *eptdev;

	eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, parent);
	if (IS_ERR(eptdev))
		return PTR_ERR(eptdev);

	return rpmsg_chrdev_eptdev_add(eptdev, chinfo);
}
EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create);

static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
{
	struct rpmsg_channel_info chinfo;
	struct rpmsg_eptdev *eptdev;
	struct device *dev = &rpdev->dev;

	memcpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
	chinfo.src = rpdev->src;
	chinfo.dst = rpdev->dst;

	eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, dev);
	if (IS_ERR(eptdev))
		return PTR_ERR(eptdev);

	/* Set the default_ept to the rpmsg device endpoint */
	eptdev->default_ept = rpdev->ept;

	/*
	 * The rpmsg_ept_cb uses *priv parameter to get its rpmsg_eptdev context.
	 * Storedit in default_ept *priv field.
	 */
	eptdev->default_ept->priv = eptdev;

	return rpmsg_chrdev_eptdev_add(eptdev, chinfo);
}

static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
{
	int ret;

	ret = device_for_each_child(&rpdev->dev, NULL, rpmsg_chrdev_eptdev_destroy);
	if (ret)
		dev_warn(&rpdev->dev, "failed to destroy endpoints: %d\n", ret);
}

static struct rpmsg_device_id rpmsg_chrdev_id_table[] = {
	{ .name	= "rpmsg-raw" },
	{ },
};

static struct rpmsg_driver rpmsg_chrdev_driver = {
	.probe = rpmsg_chrdev_probe,
	.remove = rpmsg_chrdev_remove,
	.callback = rpmsg_ept_cb,
	.id_table = rpmsg_chrdev_id_table,
	.drv.name = "rpmsg_chrdev",
};

static int rpmsg_chrdev_init(void)
{
	int ret;

	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_char");
	if (ret < 0) {
		pr_err("failed to allocate char dev region\n");
		return ret;
	}

	ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
	if (ret < 0) {
		pr_err("rpmsg: failed to register rpmsg raw driver\n");
		goto free_region;
	}

	return 0;

free_region:
	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);

	return ret;
}
postcore_initcall(rpmsg_chrdev_init);

static void rpmsg_chrdev_exit(void)
{
	unregister_rpmsg_driver(&rpmsg_chrdev_driver);
	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
}
module_exit(rpmsg_chrdev_exit);

MODULE_ALIAS("rpmsg:rpmsg_chrdev");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
136200f4	1	// SPDX-License-Identifier: GPL-2.0
c0cdc19f	2	/*
69265bc1	3	* Copyright (C) 2022, STMicroelectronics
c0cdc19f BA	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.
c0cdc19f	12	*/
c5727244 AP	13
	14	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	15
c0cdc19f BA	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/poll.h>
	23	#include <linux/rpmsg.h>
	24	#include <linux/skbuff.h>
	25	#include <linux/slab.h>
	26	#include <linux/uaccess.h>
	27	#include <uapi/linux/rpmsg.h>
	28
69265bc1	29	#include "rpmsg_char.h"
608edd96	30	#include "rpmsg_internal.h"
69265bc1	31
c0cdc19f BA	32	#define RPMSG_DEV_MAX (MINORMASK + 1)
	33
	34	static dev_t rpmsg_major;
c0cdc19f	35
c0cdc19f BA	36	static DEFINE_IDA(rpmsg_ept_ida);
	37	static DEFINE_IDA(rpmsg_minor_ida);
	38
	39	#define dev_to_eptdev(dev) container_of(dev, struct rpmsg_eptdev, dev)
	40	#define cdev_to_eptdev(i_cdev) container_of(i_cdev, struct rpmsg_eptdev, cdev)
	41
c0cdc19f BA	42	/**
	43	* struct rpmsg_eptdev - endpoint device context
	44	* @dev: endpoint device
	45	* @cdev: cdev for the endpoint device
	46	* @rpdev: underlaying rpmsg device
	47	* @chinfo: info used to open the endpoint
	48	* @ept_lock: synchronization of @ept modifications
	49	* @ept: rpmsg endpoint reference, when open
	50	* @queue_lock: synchronization of @queue operations
	51	* @queue: incoming message queue
	52	* @readq: wait object for incoming queue
bea9b79c AP	53	* @default_ept: set to channel default endpoint if the default endpoint should be re-used
bea9b79c AP	54	* on device open to prevent endpoint address update.
c0cdc19f BA	55	*/
	56	struct rpmsg_eptdev {
	57	struct device dev;
	58	struct cdev cdev;
	59
	60	struct rpmsg_device *rpdev;
	61	struct rpmsg_channel_info chinfo;
	62
	63	struct mutex ept_lock;
	64	struct rpmsg_endpoint *ept;
bea9b79c	65	struct rpmsg_endpoint *default_ept;
c0cdc19f BA	66
	67	spinlock_t queue_lock;
	68	struct sk_buff_head queue;
	69	wait_queue_head_t readq;
bea9b79c	70
c0cdc19f BA	71	};
c0cdc19f BA	72
69265bc1	73	int rpmsg_chrdev_eptdev_destroy(struct device dev, void data)
c0cdc19f BA	74	{
	75	struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
	76
	77	mutex_lock(&eptdev->ept_lock);
17b88a20	78	eptdev->rpdev = NULL;
c0cdc19f	79	if (eptdev->ept) {
467233a4 SW	80	/* The default endpoint is released by the rpmsg core */
	81	if (!eptdev->default_ept)
	82	rpmsg_destroy_ept(eptdev->ept);
c0cdc19f BA	83	eptdev->ept = NULL;
	84	}
	85	mutex_unlock(&eptdev->ept_lock);
	86
	87	/* wake up any blocked readers */
	88	wake_up_interruptible(&eptdev->readq);
	89
7a534ae8	90	cdev_device_del(&eptdev->cdev, &eptdev->dev);
c0cdc19f BA	91	put_device(&eptdev->dev);
	92
	93	return 0;
	94	}
69265bc1	95	EXPORT_SYMBOL(rpmsg_chrdev_eptdev_destroy);
c0cdc19f BA	96
	97	static int rpmsg_ept_cb(struct rpmsg_device rpdev, void buf, int len,
	98	void *priv, u32 addr)
	99	{
	100	struct rpmsg_eptdev *eptdev = priv;
	101	struct sk_buff *skb;
	102
	103	skb = alloc_skb(len, GFP_ATOMIC);
	104	if (!skb)
	105	return -ENOMEM;
	106
59ae1d12	107	skb_put_data(skb, buf, len);
c0cdc19f BA	108
	109	spin_lock(&eptdev->queue_lock);
	110	skb_queue_tail(&eptdev->queue, skb);
	111	spin_unlock(&eptdev->queue_lock);
	112
	113	/* wake up any blocking processes, waiting for new data */
	114	wake_up_interruptible(&eptdev->readq);
	115
	116	return 0;
	117	}
	118
	119	static int rpmsg_eptdev_open(struct inode inode, struct file filp)
	120	{
	121	struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
	122	struct rpmsg_endpoint *ept;
	123	struct rpmsg_device *rpdev = eptdev->rpdev;
	124	struct device *dev = &eptdev->dev;
	125
abe13e9a SW	126	mutex_lock(&eptdev->ept_lock);
	127	if (eptdev->ept) {
	128	mutex_unlock(&eptdev->ept_lock);
964e8bed	129	return -EBUSY;
abe13e9a	130	}
964e8bed	131
17b88a20 DKS	132	if (!eptdev->rpdev) {
	133	mutex_unlock(&eptdev->ept_lock);
	134	return -ENETRESET;
	135	}
	136
c0cdc19f BA	137	get_device(dev);
c0cdc19f BA	138
bea9b79c AP	139	/*
	140	* If the default_ept is set, the rpmsg device default endpoint is used.
	141	* Else a new endpoint is created on open that will be destroyed on release.
	142	*/
	143	if (eptdev->default_ept)
	144	ept = eptdev->default_ept;
	145	else
	146	ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo);
	147
c0cdc19f BA	148	if (!ept) {
	149	dev_err(dev, "failed to open %s\n", eptdev->chinfo.name);
	150	put_device(dev);
abe13e9a	151	mutex_unlock(&eptdev->ept_lock);
c0cdc19f BA	152	return -EINVAL;
	153	}
	154
	155	eptdev->ept = ept;
	156	filp->private_data = eptdev;
abe13e9a	157	mutex_unlock(&eptdev->ept_lock);
c0cdc19f BA	158
	159	return 0;
	160	}
	161
	162	static int rpmsg_eptdev_release(struct inode inode, struct file filp)
	163	{
	164	struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev);
	165	struct device *dev = &eptdev->dev;
c0cdc19f BA	166
	167	/* Close the endpoint, if it's not already destroyed by the parent */
	168	mutex_lock(&eptdev->ept_lock);
	169	if (eptdev->ept) {
bea9b79c AP	170	if (!eptdev->default_ept)
bea9b79c AP	171	rpmsg_destroy_ept(eptdev->ept);
c0cdc19f BA	172	eptdev->ept = NULL;
	173	}
	174	mutex_unlock(&eptdev->ept_lock);
	175
	176	/* Discard all SKBs */
bb06a5ce	177	skb_queue_purge(&eptdev->queue);
c0cdc19f BA	178
	179	put_device(dev);
	180
	181	return 0;
	182	}
	183
ccf45b18	184	static ssize_t rpmsg_eptdev_read_iter(struct kiocb iocb, struct iov_iter to)
c0cdc19f	185	{
ccf45b18	186	struct file *filp = iocb->ki_filp;
c0cdc19f BA	187	struct rpmsg_eptdev *eptdev = filp->private_data;
	188	unsigned long flags;
	189	struct sk_buff *skb;
	190	int use;
	191
	192	if (!eptdev->ept)
	193	return -EPIPE;
	194
	195	spin_lock_irqsave(&eptdev->queue_lock, flags);
	196
	197	/* Wait for data in the queue */
	198	if (skb_queue_empty(&eptdev->queue)) {
	199	spin_unlock_irqrestore(&eptdev->queue_lock, flags);
	200
	201	if (filp->f_flags & O_NONBLOCK)
	202	return -EAGAIN;
	203
	204	/* Wait until we get data or the endpoint goes away */
	205	if (wait_event_interruptible(eptdev->readq,
	206	!skb_queue_empty(&eptdev->queue) \|\|
	207	!eptdev->ept))
	208	return -ERESTARTSYS;
	209
	210	/* We lost the endpoint while waiting */
	211	if (!eptdev->ept)
	212	return -EPIPE;
	213
	214	spin_lock_irqsave(&eptdev->queue_lock, flags);
	215	}
	216
	217	skb = skb_dequeue(&eptdev->queue);
0abd6bdd	218	spin_unlock_irqrestore(&eptdev->queue_lock, flags);
c0cdc19f BA	219	if (!skb)
	220	return -EFAULT;
	221
ccf45b18 BA	222	use = min_t(size_t, iov_iter_count(to), skb->len);
ccf45b18 BA	223	if (copy_to_iter(skb->data, use, to) != use)
c0cdc19f BA	224	use = -EFAULT;
	225
	226	kfree_skb(skb);
	227
	228	return use;
	229	}
	230
ccf45b18 BA	231	static ssize_t rpmsg_eptdev_write_iter(struct kiocb *iocb,
ccf45b18 BA	232	struct iov_iter *from)
c0cdc19f	233	{
ccf45b18	234	struct file *filp = iocb->ki_filp;
c0cdc19f	235	struct rpmsg_eptdev *eptdev = filp->private_data;
ccf45b18	236	size_t len = iov_iter_count(from);
c0cdc19f BA	237	void *kbuf;
	238	int ret;
	239
ccf45b18 BA	240	kbuf = kzalloc(len, GFP_KERNEL);
	241	if (!kbuf)
	242	return -ENOMEM;
	243
bbe692e3 NE	244	if (!copy_from_iter_full(kbuf, len, from)) {
	245	ret = -EFAULT;
	246	goto free_kbuf;
	247	}
c0cdc19f BA	248
	249	if (mutex_lock_interruptible(&eptdev->ept_lock)) {
	250	ret = -ERESTARTSYS;
	251	goto free_kbuf;
	252	}
	253
	254	if (!eptdev->ept) {
	255	ret = -EPIPE;
	256	goto unlock_eptdev;
	257	}
	258
cbf58250	259	if (filp->f_flags & O_NONBLOCK) {
b4ce7e2e	260	ret = rpmsg_trysendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst);
cbf58250 TB	261	if (ret == -ENOMEM)
	262	ret = -EAGAIN;
	263	} else {
b4ce7e2e	264	ret = rpmsg_sendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst);
cbf58250	265	}
c0cdc19f BA	266
	267	unlock_eptdev:
	268	mutex_unlock(&eptdev->ept_lock);
	269
	270	free_kbuf:
	271	kfree(kbuf);
	272	return ret < 0 ? ret : len;
	273	}
	274
afc9a42b	275	static __poll_t rpmsg_eptdev_poll(struct file filp, poll_table wait)
c0cdc19f BA	276	{
c0cdc19f BA	277	struct rpmsg_eptdev *eptdev = filp->private_data;
afc9a42b	278	__poll_t mask = 0;
c0cdc19f BA	279
c0cdc19f BA	280	if (!eptdev->ept)
a9a08845	281	return EPOLLERR;
c0cdc19f BA	282
	283	poll_wait(filp, &eptdev->readq, wait);
	284
	285	if (!skb_queue_empty(&eptdev->queue))
a9a08845	286	mask \|= EPOLLIN \| EPOLLRDNORM;
c0cdc19f	287
17b88a20	288	mutex_lock(&eptdev->ept_lock);
c0cdc19f	289	mask \|= rpmsg_poll(eptdev->ept, filp, wait);
17b88a20	290	mutex_unlock(&eptdev->ept_lock);
c0cdc19f BA	291
	292	return mask;
	293	}
	294
	295	static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
	296	unsigned long arg)
	297	{
	298	struct rpmsg_eptdev *eptdev = fp->private_data;
	299
	300	if (cmd != RPMSG_DESTROY_EPT_IOCTL)
	301	return -EINVAL;
	302
bea9b79c AP	303	/* Don't allow to destroy a default endpoint. */
	304	if (eptdev->default_ept)
	305	return -EINVAL;
	306
69265bc1	307	return rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
c0cdc19f BA	308	}
	309
	310	static const struct file_operations rpmsg_eptdev_fops = {
	311	.owner = THIS_MODULE,
	312	.open = rpmsg_eptdev_open,
	313	.release = rpmsg_eptdev_release,
ccf45b18 BA	314	.read_iter = rpmsg_eptdev_read_iter,
ccf45b18 BA	315	.write_iter = rpmsg_eptdev_write_iter,
c0cdc19f BA	316	.poll = rpmsg_eptdev_poll,
c0cdc19f BA	317	.unlocked_ioctl = rpmsg_eptdev_ioctl,
1832f2d8	318	.compat_ioctl = compat_ptr_ioctl,
c0cdc19f BA	319	};
	320
	321	static ssize_t name_show(struct device dev, struct device_attribute attr,
	322	char *buf)
	323	{
	324	struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
	325
	326	return sprintf(buf, "%s\n", eptdev->chinfo.name);
	327	}
	328	static DEVICE_ATTR_RO(name);
	329
	330	static ssize_t src_show(struct device dev, struct device_attribute attr,
	331	char *buf)
	332	{
	333	struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
	334
	335	return sprintf(buf, "%d\n", eptdev->chinfo.src);
	336	}
	337	static DEVICE_ATTR_RO(src);
	338
	339	static ssize_t dst_show(struct device dev, struct device_attribute attr,
	340	char *buf)
	341	{
	342	struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev);
	343
	344	return sprintf(buf, "%d\n", eptdev->chinfo.dst);
	345	}
	346	static DEVICE_ATTR_RO(dst);
	347
	348	static struct attribute *rpmsg_eptdev_attrs[] = {
	349	&dev_attr_name.attr,
	350	&dev_attr_src.attr,
	351	&dev_attr_dst.attr,
	352	NULL
	353	};
	354	ATTRIBUTE_GROUPS(rpmsg_eptdev);
	355
	356	static void rpmsg_eptdev_release_device(struct device *dev)
	357	{
	358	struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev);
	359
	360	ida_simple_remove(&rpmsg_ept_ida, dev->id);
	361	ida_simple_remove(&rpmsg_minor_ida, MINOR(eptdev->dev.devt));
c0cdc19f BA	362	kfree(eptdev);
	363	}
	364
cc9da7de AP	365	static struct rpmsg_eptdev rpmsg_chrdev_eptdev_alloc(struct rpmsg_device rpdev,
cc9da7de AP	366	struct device *parent)
c0cdc19f	367	{
c0cdc19f BA	368	struct rpmsg_eptdev *eptdev;
c0cdc19f BA	369	struct device *dev;
c0cdc19f BA	370
	371	eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL);
	372	if (!eptdev)
cc9da7de	373	return ERR_PTR(-ENOMEM);
c0cdc19f BA	374
	375	dev = &eptdev->dev;
	376	eptdev->rpdev = rpdev;
c0cdc19f BA	377
	378	mutex_init(&eptdev->ept_lock);
	379	spin_lock_init(&eptdev->queue_lock);
	380	skb_queue_head_init(&eptdev->queue);
	381	init_waitqueue_head(&eptdev->readq);
	382
	383	device_initialize(dev);
	384	dev->class = rpmsg_class;
69265bc1	385	dev->parent = parent;
c0cdc19f BA	386	dev->groups = rpmsg_eptdev_groups;
	387	dev_set_drvdata(dev, eptdev);
	388
	389	cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops);
	390	eptdev->cdev.owner = THIS_MODULE;
	391
cc9da7de AP	392	return eptdev;
	393	}
	394
	395	static int rpmsg_chrdev_eptdev_add(struct rpmsg_eptdev *eptdev, struct rpmsg_channel_info chinfo)
	396	{
	397	struct device *dev = &eptdev->dev;
	398	int ret;
	399
	400	eptdev->chinfo = chinfo;
	401
c0cdc19f BA	402	ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
	403	if (ret < 0)
	404	goto free_eptdev;
	405	dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
	406
	407	ret = ida_simple_get(&rpmsg_ept_ida, 0, 0, GFP_KERNEL);
	408	if (ret < 0)
	409	goto free_minor_ida;
	410	dev->id = ret;
	411	dev_set_name(dev, "rpmsg%d", ret);
	412
7a534ae8	413	ret = cdev_device_add(&eptdev->cdev, &eptdev->dev);
c0cdc19f BA	414	if (ret)
	415	goto free_ept_ida;
	416
	417	/* We can now rely on the release function for cleanup */
	418	dev->release = rpmsg_eptdev_release_device;
	419
c0cdc19f BA	420	return ret;
	421
	422	free_ept_ida:
	423	ida_simple_remove(&rpmsg_ept_ida, dev->id);
	424	free_minor_ida:
	425	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
	426	free_eptdev:
	427	put_device(dev);
	428	kfree(eptdev);
	429
	430	return ret;
	431	}
cc9da7de AP	432
	433	int rpmsg_chrdev_eptdev_create(struct rpmsg_device rpdev, struct device parent,
	434	struct rpmsg_channel_info chinfo)
	435	{
	436	struct rpmsg_eptdev *eptdev;
cc9da7de AP	437
	438	eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, parent);
	439	if (IS_ERR(eptdev))
	440	return PTR_ERR(eptdev);
	441
06564be4	442	return rpmsg_chrdev_eptdev_add(eptdev, chinfo);
cc9da7de	443	}
69265bc1	444	EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create);
c0cdc19f	445
bc69d106 AP	446	static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
	447	{
	448	struct rpmsg_channel_info chinfo;
	449	struct rpmsg_eptdev *eptdev;
	450	struct device *dev = &rpdev->dev;
	451
	452	memcpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
	453	chinfo.src = rpdev->src;
	454	chinfo.dst = rpdev->dst;
	455
	456	eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, dev);
	457	if (IS_ERR(eptdev))
	458	return PTR_ERR(eptdev);
	459
	460	/* Set the default_ept to the rpmsg device endpoint */
	461	eptdev->default_ept = rpdev->ept;
	462
	463	/*
	464	* The rpmsg_ept_cb uses *priv parameter to get its rpmsg_eptdev context.
	465	* Storedit in default_ept *priv field.
	466	*/
	467	eptdev->default_ept->priv = eptdev;
	468
	469	return rpmsg_chrdev_eptdev_add(eptdev, chinfo);
	470	}
	471
	472	static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
	473	{
	474	int ret;
	475
	476	ret = device_for_each_child(&rpdev->dev, NULL, rpmsg_chrdev_eptdev_destroy);
	477	if (ret)
	478	dev_warn(&rpdev->dev, "failed to destroy endpoints: %d\n", ret);
	479	}
	480
	481	static struct rpmsg_device_id rpmsg_chrdev_id_table[] = {
	482	{ .name = "rpmsg-raw" },
	483	{ },
	484	};
	485
	486	static struct rpmsg_driver rpmsg_chrdev_driver = {
	487	.probe = rpmsg_chrdev_probe,
	488	.remove = rpmsg_chrdev_remove,
	489	.callback = rpmsg_ept_cb,
	490	.id_table = rpmsg_chrdev_id_table,
	491	.drv.name = "rpmsg_chrdev",
	492	};
	493
60d7b22d	494	static int rpmsg_chrdev_init(void)
c0cdc19f BA	495	{
	496	int ret;
	497
617d3293	498	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_char");
c0cdc19f	499	if (ret < 0) {
c5727244	500	pr_err("failed to allocate char dev region\n");
c0cdc19f BA	501	return ret;
	502	}
	503
bc69d106 AP	504	ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
	505	if (ret < 0) {
	506	pr_err("rpmsg: failed to register rpmsg raw driver\n");
	507	goto free_region;
	508	}
	509
617d3293	510	return 0;
bc69d106 AP	511
	512	free_region:
	513	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
	514
	515	return ret;
c0cdc19f	516	}
60d7b22d	517	postcore_initcall(rpmsg_chrdev_init);
c0cdc19f BA	518
	519	static void rpmsg_chrdev_exit(void)
	520	{
bc69d106	521	unregister_rpmsg_driver(&rpmsg_chrdev_driver);
c0cdc19f BA	522	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
	523	}
	524	module_exit(rpmsg_chrdev_exit);
93dd4e73 RF	525
93dd4e73 RF	526	MODULE_ALIAS("rpmsg:rpmsg_chrdev");
c0cdc19f	527	MODULE_LICENSE("GPL v2");