[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);
	if (eptdev->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;

	if (eptdev->ept)
		return -EBUSY;

	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);
		return -EINVAL;
	}

	eptdev->ept = ept;
	filp->private_data = eptdev;

	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;

	mask |= rpmsg_poll(eptdev->ept, filp, wait);

	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;
	int ret;

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

	ret = rpmsg_chrdev_eptdev_add(eptdev, chinfo);

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