diff mbox series

[v2,2/7] rpmsg: Move the rpmsg control device from rpmsg_char to rpmsg_ctrl

Message ID 20210413134458.17912-3-arnaud.pouliquen@foss.st.com (mailing list archive)
State Superseded
Headers show
Series Restructure the rpmsg char and introduce the rpmsg-raw channel | expand

Commit Message

Arnaud POULIQUEN April 13, 2021, 1:44 p.m. UTC
Create the rpmsg_ctrl.c module and move the code related to the
rpmsg_ctrldev device in this new module.

Add the dependency between rpmsg_char and rpmsg_ctrl in the
kconfig file.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
---
update from v1:
- keep "rpmsg_chrdev" driver name in rpmsg_ctrl, driver will be renamed
  in next path that renames the rpmsg_chrdev_create_eptdev.
- rename the chardev regions
- move RPMSG_DEV_MAX to rpmsg_char.h
---
 drivers/rpmsg/Kconfig      |   9 ++
 drivers/rpmsg/Makefile     |   1 +
 drivers/rpmsg/rpmsg_char.c | 181 +----------------------------
 drivers/rpmsg/rpmsg_char.h |   2 +
 drivers/rpmsg/rpmsg_ctrl.c | 231 +++++++++++++++++++++++++++++++++++++
 5 files changed, 245 insertions(+), 179 deletions(-)
 create mode 100644 drivers/rpmsg/rpmsg_ctrl.c

Comments

Mathieu Poirier April 21, 2021, 6:04 p.m. UTC | #1
On Tue, Apr 13, 2021 at 03:44:53PM +0200, Arnaud Pouliquen wrote:
> Create the rpmsg_ctrl.c module and move the code related to the
> rpmsg_ctrldev device in this new module.
> 
> Add the dependency between rpmsg_char and rpmsg_ctrl in the
> kconfig file.
> 
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
> ---
> update from v1:
> - keep "rpmsg_chrdev" driver name in rpmsg_ctrl, driver will be renamed
>   in next path that renames the rpmsg_chrdev_create_eptdev.
> - rename the chardev regions
> - move RPMSG_DEV_MAX to rpmsg_char.h
> ---
>  drivers/rpmsg/Kconfig      |   9 ++
>  drivers/rpmsg/Makefile     |   1 +
>  drivers/rpmsg/rpmsg_char.c | 181 +----------------------------
>  drivers/rpmsg/rpmsg_char.h |   2 +
>  drivers/rpmsg/rpmsg_ctrl.c | 231 +++++++++++++++++++++++++++++++++++++
>  5 files changed, 245 insertions(+), 179 deletions(-)
>  create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
> 
> diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
> index 0b4407abdf13..d822ec9ec692 100644
> --- a/drivers/rpmsg/Kconfig
> +++ b/drivers/rpmsg/Kconfig
> @@ -10,11 +10,20 @@ config RPMSG_CHAR
>  	tristate "RPMSG device interface"
>  	depends on RPMSG
>  	depends on NET
> +	select RPMSG_CTRL
>  	help
>  	  Say Y here to export rpmsg endpoints as device files, usually found
>  	  in /dev. They make it possible for user-space programs to send and
>  	  receive rpmsg packets.
>  
> +config RPMSG_CTRL
> +	tristate "RPMSG control interface"
> +	depends on RPMSG
> +	help
> +	  Say Y here to enable the support of the /dev/rpmsg_ctrlX API. This API
> +	  allows user-space programs to create endpoints with specific service name,
> +	  source and destination addresses.
> +
>  config RPMSG_NS
>  	tristate "RPMSG name service announcement"
>  	depends on RPMSG
> diff --git a/drivers/rpmsg/Makefile b/drivers/rpmsg/Makefile
> index 8d452656f0ee..58e3b382e316 100644
> --- a/drivers/rpmsg/Makefile
> +++ b/drivers/rpmsg/Makefile
> @@ -1,6 +1,7 @@
>  # SPDX-License-Identifier: GPL-2.0
>  obj-$(CONFIG_RPMSG)		+= rpmsg_core.o
>  obj-$(CONFIG_RPMSG_CHAR)	+= rpmsg_char.o
> +obj-$(CONFIG_RPMSG_CTRL)	+= rpmsg_ctrl.o
>  obj-$(CONFIG_RPMSG_NS)		+= rpmsg_ns.o
>  obj-$(CONFIG_RPMSG_MTK_SCP)	+= mtk_rpmsg.o
>  qcom_glink-objs			:= qcom_glink_native.o qcom_glink_ssr.o
> diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
> index b9df8dc4365f..21ef9d9eccd7 100644
> --- a/drivers/rpmsg/rpmsg_char.c
> +++ b/drivers/rpmsg/rpmsg_char.c
> @@ -26,33 +26,14 @@
>  #include "rpmsg_char.h"
>  #include "rpmsg_internal.h"
>  
> -#define RPMSG_DEV_MAX	(MINORMASK + 1)
> -
>  static dev_t rpmsg_major;
> -static struct class *rpmsg_class;
>  
> -static DEFINE_IDA(rpmsg_ctrl_ida);
>  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)
>  
> -#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev)
> -#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev)
> -
> -/**
> - * struct rpmsg_ctrldev - control device for instantiating endpoint devices
> - * @rpdev:	underlaying rpmsg device
> - * @cdev:	cdev for the ctrl device
> - * @dev:	device for the ctrl device
> - */
> -struct rpmsg_ctrldev {
> -	struct rpmsg_device *rpdev;
> -	struct cdev cdev;
> -	struct device dev;
> -};
> -
>  /**
>   * struct rpmsg_eptdev - endpoint device context
>   * @dev:	endpoint device
> @@ -409,169 +390,13 @@ int rpmsg_chrdev_create_eptdev(struct rpmsg_device *rpdev, struct device *parent
>  }
>  EXPORT_SYMBOL(rpmsg_chrdev_create_eptdev);
>  
> -static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp)
> -{
> -	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
> -
> -	get_device(&ctrldev->dev);
> -	filp->private_data = ctrldev;
> -
> -	return 0;
> -}
> -
> -static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp)
> -{
> -	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
> -
> -	put_device(&ctrldev->dev);
> -
> -	return 0;
> -}
> -
> -static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd,
> -				unsigned long arg)
> -{
> -	struct rpmsg_ctrldev *ctrldev = fp->private_data;
> -	void __user *argp = (void __user *)arg;
> -	struct rpmsg_endpoint_info eptinfo;
> -	struct rpmsg_channel_info chinfo;
> -
> -	if (cmd != RPMSG_CREATE_EPT_IOCTL)
> -		return -EINVAL;
> -
> -	if (copy_from_user(&eptinfo, argp, sizeof(eptinfo)))
> -		return -EFAULT;
> -
> -	memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE);
> -	chinfo.name[RPMSG_NAME_SIZE-1] = '\0';
> -	chinfo.src = eptinfo.src;
> -	chinfo.dst = eptinfo.dst;
> -
> -	return rpmsg_chrdev_create_eptdev(ctrldev->rpdev, &ctrldev->dev, chinfo, rpmsg_class);
> -};
> -
> -static const struct file_operations rpmsg_ctrldev_fops = {
> -	.owner = THIS_MODULE,
> -	.open = rpmsg_ctrldev_open,
> -	.release = rpmsg_ctrldev_release,
> -	.unlocked_ioctl = rpmsg_ctrldev_ioctl,
> -	.compat_ioctl = compat_ptr_ioctl,
> -};
> -
> -static void rpmsg_ctrldev_release_device(struct device *dev)
> -{
> -	struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev);
> -
> -	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
> -	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
> -	cdev_del(&ctrldev->cdev);
> -	kfree(ctrldev);
> -}
> -
> -static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
> -{
> -	struct rpmsg_ctrldev *ctrldev;
> -	struct device *dev;
> -	int ret;
> -
> -	ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL);
> -	if (!ctrldev)
> -		return -ENOMEM;
> -
> -	ctrldev->rpdev = rpdev;
> -
> -	dev = &ctrldev->dev;
> -	device_initialize(dev);
> -	dev->parent = &rpdev->dev;
> -	dev->class = rpmsg_class;
> -
> -	cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
> -	ctrldev->cdev.owner = THIS_MODULE;
> -
> -	ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
> -	if (ret < 0)
> -		goto free_ctrldev;
> -	dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
> -
> -	ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL);
> -	if (ret < 0)
> -		goto free_minor_ida;
> -	dev->id = ret;
> -	dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret);
> -
> -	ret = cdev_add(&ctrldev->cdev, dev->devt, 1);
> -	if (ret)
> -		goto free_ctrl_ida;
> -
> -	/* We can now rely on the release function for cleanup */
> -	dev->release = rpmsg_ctrldev_release_device;
> -
> -	ret = device_add(dev);
> -	if (ret) {
> -		dev_err(&rpdev->dev, "device_add failed: %d\n", ret);
> -		put_device(dev);
> -	}
> -
> -	dev_set_drvdata(&rpdev->dev, ctrldev);
> -
> -	return ret;
> -
> -free_ctrl_ida:
> -	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
> -free_minor_ida:
> -	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
> -free_ctrldev:
> -	put_device(dev);
> -	kfree(ctrldev);
> -
> -	return ret;
> -}
> -
> -static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
> -{
> -	struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev);
> -	int ret;
> -
> -	/* Destroy all endpoints */
> -	ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_chrdev_destroy_eptdev);
> -	if (ret)
> -		dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
> -
> -	device_del(&ctrldev->dev);
> -	put_device(&ctrldev->dev);
> -}
> -
> -static struct rpmsg_driver rpmsg_chrdev_driver = {
> -	.probe = rpmsg_chrdev_probe,
> -	.remove = rpmsg_chrdev_remove,
> -	.drv = {
> -		.name = "rpmsg_chrdev",
> -	},
> -};
> -
>  static int rpmsg_chrdev_init(void)
>  {
>  	int ret;
>  
> -	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg");
> -	if (ret < 0) {
> +	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_char");
> +	if (ret < 0)
>  		pr_err("rpmsg: failed to allocate char dev region\n");
> -		return ret;
> -	}
> -
> -	rpmsg_class = class_create(THIS_MODULE, "rpmsg");
> -	if (IS_ERR(rpmsg_class)) {
> -		pr_err("failed to create rpmsg class\n");
> -		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
> -		return PTR_ERR(rpmsg_class);
> -	}
> -
> -	ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
> -	if (ret < 0) {
> -		pr_err("rpmsgchr: failed to register rpmsg driver\n");
> -		class_destroy(rpmsg_class);
> -		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
> -	}
>  
>  	return ret;
>  }
> @@ -579,8 +404,6 @@ postcore_initcall(rpmsg_chrdev_init);
>  
>  static void rpmsg_chrdev_exit(void)
>  {
> -	unregister_rpmsg_driver(&rpmsg_chrdev_driver);
> -	class_destroy(rpmsg_class);
>  	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
>  }
>  module_exit(rpmsg_chrdev_exit);
> diff --git a/drivers/rpmsg/rpmsg_char.h b/drivers/rpmsg/rpmsg_char.h
> index 379d2ae2bee8..f20a215073c3 100644
> --- a/drivers/rpmsg/rpmsg_char.h
> +++ b/drivers/rpmsg/rpmsg_char.h
> @@ -6,6 +6,8 @@
>  #ifndef __RPMSG_CHRDEV_H__
>  #define __RPMSG_CHRDEV_H__
>  
> +#define RPMSG_DEV_MAX	(MINORMASK + 1)
> +
>  #if IS_REACHABLE(CONFIG_RPMSG_CHAR)
>  /**
>   * rpmsg_chrdev_create_eptdev() - register char device based on an endpoint
> diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
> new file mode 100644
> index 000000000000..a5bb9ed97f32
> --- /dev/null
> +++ b/drivers/rpmsg/rpmsg_ctrl.c
> @@ -0,0 +1,231 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021, 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.
> + */
> +#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/rpmsg.h>
> +#include <linux/slab.h>
> +#include <uapi/linux/rpmsg.h>
> +
> +#include "rpmsg_char.h"
> +#include "rpmsg_internal.h"
> +
> +static dev_t rpmsg_major;
> +struct class *rpmsg_class;
> +
> +static DEFINE_IDA(rpmsg_ctrl_ida);
> +static DEFINE_IDA(rpmsg_minor_ida);
> +
> +#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev)
> +#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev)
> +
> +/**
> + * struct rpmsg_ctrldev - control device for instantiating endpoint devices
> + * @rpdev:	underlaying rpmsg device
> + * @cdev:	cdev for the ctrl device
> + * @dev:	device for the ctrl device
> + */
> +struct rpmsg_ctrldev {
> +	struct rpmsg_device *rpdev;
> +	struct cdev cdev;
> +	struct device dev;
> +};
> +
> +static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp)
> +{
> +	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
> +
> +	get_device(&ctrldev->dev);
> +	filp->private_data = ctrldev;
> +
> +	return 0;
> +}
> +
> +static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp)
> +{
> +	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
> +
> +	put_device(&ctrldev->dev);
> +
> +	return 0;
> +}
> +
> +static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd,
> +				unsigned long arg)
> +{
> +	struct rpmsg_ctrldev *ctrldev = fp->private_data;
> +	void __user *argp = (void __user *)arg;
> +	struct rpmsg_endpoint_info eptinfo;
> +	struct rpmsg_channel_info chinfo;
> +
> +	if (cmd != RPMSG_CREATE_EPT_IOCTL)
> +		return -EINVAL;
> +
> +	if (copy_from_user(&eptinfo, argp, sizeof(eptinfo)))
> +		return -EFAULT;
> +
> +	memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE);
> +	chinfo.name[RPMSG_NAME_SIZE - 1] = '\0';
> +	chinfo.src = eptinfo.src;
> +	chinfo.dst = eptinfo.dst;
> +
> +	return rpmsg_chrdev_create_eptdev(ctrldev->rpdev, &ctrldev->dev, chinfo, rpmsg_class);
> +};
> +
> +static const struct file_operations rpmsg_ctrldev_fops = {
> +	.owner = THIS_MODULE,
> +	.open = rpmsg_ctrldev_open,
> +	.release = rpmsg_ctrldev_release,
> +	.unlocked_ioctl = rpmsg_ctrldev_ioctl,
> +	.compat_ioctl = compat_ptr_ioctl,
> +};
> +
> +static void rpmsg_ctrldev_release_device(struct device *dev)
> +{
> +	struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev);
> +
> +	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
> +	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
> +	cdev_del(&ctrldev->cdev);
> +	kfree(ctrldev);
> +}
> +
> +static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev)
> +{
> +	struct rpmsg_ctrldev *ctrldev;
> +	struct device *dev;
> +	int ret;
> +
> +	ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL);
> +	if (!ctrldev)
> +		return -ENOMEM;
> +
> +	ctrldev->rpdev = rpdev;
> +
> +	dev = &ctrldev->dev;
> +	device_initialize(dev);
> +	dev->parent = &rpdev->dev;
> +	dev->class = rpmsg_class;
> +
> +	cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
> +	ctrldev->cdev.owner = THIS_MODULE;
> +
> +	ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
> +	if (ret < 0)
> +		goto free_ctrldev;
> +	dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
> +
> +	ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL);
> +	if (ret < 0)
> +		goto free_minor_ida;
> +	dev->id = ret;
> +	dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret);
> +
> +	ret = cdev_add(&ctrldev->cdev, dev->devt, 1);
> +	if (ret)
> +		goto free_ctrl_ida;
> +
> +	/* We can now rely on the release function for cleanup */
> +	dev->release = rpmsg_ctrldev_release_device;
> +
> +	ret = device_add(dev);
> +	if (ret) {
> +		dev_err(&rpdev->dev, "device_add failed: %d\n", ret);
> +		put_device(dev);
> +	}
> +
> +	dev_set_drvdata(&rpdev->dev, ctrldev);
> +
> +	return ret;
> +
> +free_ctrl_ida:
> +	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
> +free_minor_ida:
> +	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
> +free_ctrldev:
> +	put_device(dev);
> +	kfree(ctrldev);
> +
> +	return ret;
> +}
> +
> +static void rpmsg_ctrldev_remove(struct rpmsg_device *rpdev)
> +{
> +	struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev);
> +	int ret;
> +
> +	/* Destroy all endpoints */
> +	ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_chrdev_destroy_eptdev);
> +	if (ret)
> +		dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
> +
> +	device_del(&ctrldev->dev);
> +	put_device(&ctrldev->dev);
> +}
> +
> +static struct rpmsg_driver rpmsg_ctrldev_driver = {
> +	.probe = rpmsg_ctrldev_probe,
> +	.remove = rpmsg_ctrldev_remove,
> +	.drv = {
> +		.name = "rpmsg_chrdev",
> +	},
> +};
> +
> +static int rpmsg_ctrldev_init(void)
> +{
> +	int ret;
> +
> +	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl");
> +	if (ret < 0) {
> +		pr_err("rpmsg: failed to allocate char dev region\n");
> +		return ret;
> +	}
> +
> +	rpmsg_class = class_create(THIS_MODULE, "rpmsg");

This class thing really bothers me.  Keeping this here means that rpmsg_eptdevs
created from user space will be associated to this rpmsg_class but those created
from the name service won't.  As such I propose to move this to rpmsg_char and
simply not associate the control device to the class.

Otherwise we'd have to introduce some mechanic only to deal with the creation of
the class and I don't think it is worth.  We can revise that approach if someone
complains we broke their user space. 


> +	if (IS_ERR(rpmsg_class)) {
> +		pr_err("failed to create rpmsg class\n");
> +		ret = PTR_ERR(rpmsg_class);
> +		goto free_region;
> +	}
> +
> +	ret = register_rpmsg_driver(&rpmsg_ctrldev_driver);
> +	if (ret < 0) {
> +		pr_err("rpmsg ctrl: failed to register rpmsg driver\n");
> +		goto free_class;
> +	}
> +
> +	return 0;
> +
> +free_class:
> +	class_destroy(rpmsg_class);
> +free_region:
> +	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
> +
> +	return ret;
> +}
> +postcore_initcall(rpmsg_ctrldev_init);
> +
> +static void rpmsg_ctrldev_exit(void)
> +{
> +	unregister_rpmsg_driver(&rpmsg_ctrldev_driver);
> +	class_destroy(rpmsg_class);
> +	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
> +}
> +module_exit(rpmsg_ctrldev_exit);
> +
> +MODULE_DESCRIPTION("rpmsg control interface");
> +MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.17.1
>
Arnaud POULIQUEN April 22, 2021, 7:56 a.m. UTC | #2
On 4/21/21 8:04 PM, Mathieu Poirier wrote:
> On Tue, Apr 13, 2021 at 03:44:53PM +0200, Arnaud Pouliquen wrote:
>> Create the rpmsg_ctrl.c module and move the code related to the
>> rpmsg_ctrldev device in this new module.
>>
>> Add the dependency between rpmsg_char and rpmsg_ctrl in the
>> kconfig file.
>>
>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
>> ---
>> update from v1:
>> - keep "rpmsg_chrdev" driver name in rpmsg_ctrl, driver will be renamed
>>   in next path that renames the rpmsg_chrdev_create_eptdev.
>> - rename the chardev regions
>> - move RPMSG_DEV_MAX to rpmsg_char.h
>> ---
>>  drivers/rpmsg/Kconfig      |   9 ++
>>  drivers/rpmsg/Makefile     |   1 +
>>  drivers/rpmsg/rpmsg_char.c | 181 +----------------------------
>>  drivers/rpmsg/rpmsg_char.h |   2 +
>>  drivers/rpmsg/rpmsg_ctrl.c | 231 +++++++++++++++++++++++++++++++++++++
>>  5 files changed, 245 insertions(+), 179 deletions(-)
>>  create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
>>
>> diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
>> index 0b4407abdf13..d822ec9ec692 100644
>> --- a/drivers/rpmsg/Kconfig

snip[...]

>> +static int rpmsg_ctrldev_init(void)
>> +{
>> +	int ret;
>> +
>> +	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl");
>> +	if (ret < 0) {
>> +		pr_err("rpmsg: failed to allocate char dev region\n");
>> +		return ret;
>> +	}
>> +
>> +	rpmsg_class = class_create(THIS_MODULE, "rpmsg");
> 
> This class thing really bothers me.  Keeping this here means that rpmsg_eptdevs
> created from user space will be associated to this rpmsg_class but those created
> from the name service won't.  As such I propose to move this to rpmsg_char and
> simply not associate the control device to the class.
> 
> Otherwise we'd have to introduce some mechanic only to deal with the creation of
> the class and I don't think it is worth.  We can revise that approach if someone
> complains we broke their user space. 

I agree with that as it was my first proposed approach here [1]

[1] https://www.spinics.net/lists/linux-arm-msm/msg81194.html

Thanks,
Arnaud

> 
> 
>> +	if (IS_ERR(rpmsg_class)) {
>> +		pr_err("failed to create rpmsg class\n");
>> +		ret = PTR_ERR(rpmsg_class);
>> +		goto free_region;
>> +	}
>> +
>> +	ret = register_rpmsg_driver(&rpmsg_ctrldev_driver);
>> +	if (ret < 0) {
>> +		pr_err("rpmsg ctrl: failed to register rpmsg driver\n");
>> +		goto free_class;
>> +	}
>> +
>> +	return 0;
>> +
>> +free_class:
>> +	class_destroy(rpmsg_class);
>> +free_region:
>> +	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
>> +
>> +	return ret;
>> +}
>> +postcore_initcall(rpmsg_ctrldev_init);
>> +
>> +static void rpmsg_ctrldev_exit(void)
>> +{
>> +	unregister_rpmsg_driver(&rpmsg_ctrldev_driver);
>> +	class_destroy(rpmsg_class);
>> +	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
>> +}
>> +module_exit(rpmsg_ctrldev_exit);
>> +
>> +MODULE_DESCRIPTION("rpmsg control interface");
>> +MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
>> +MODULE_LICENSE("GPL v2");
>> -- 
>> 2.17.1
>>
Mathieu Poirier April 22, 2021, 4:32 p.m. UTC | #3
On Thu, Apr 22, 2021 at 09:56:41AM +0200, Arnaud POULIQUEN wrote:
> 
> 
> On 4/21/21 8:04 PM, Mathieu Poirier wrote:
> > On Tue, Apr 13, 2021 at 03:44:53PM +0200, Arnaud Pouliquen wrote:
> >> Create the rpmsg_ctrl.c module and move the code related to the
> >> rpmsg_ctrldev device in this new module.
> >>
> >> Add the dependency between rpmsg_char and rpmsg_ctrl in the
> >> kconfig file.
> >>
> >> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
> >> ---
> >> update from v1:
> >> - keep "rpmsg_chrdev" driver name in rpmsg_ctrl, driver will be renamed
> >>   in next path that renames the rpmsg_chrdev_create_eptdev.
> >> - rename the chardev regions
> >> - move RPMSG_DEV_MAX to rpmsg_char.h
> >> ---
> >>  drivers/rpmsg/Kconfig      |   9 ++
> >>  drivers/rpmsg/Makefile     |   1 +
> >>  drivers/rpmsg/rpmsg_char.c | 181 +----------------------------
> >>  drivers/rpmsg/rpmsg_char.h |   2 +
> >>  drivers/rpmsg/rpmsg_ctrl.c | 231 +++++++++++++++++++++++++++++++++++++
> >>  5 files changed, 245 insertions(+), 179 deletions(-)
> >>  create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
> >>
> >> diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
> >> index 0b4407abdf13..d822ec9ec692 100644
> >> --- a/drivers/rpmsg/Kconfig
> 
> snip[...]
> 
> >> +static int rpmsg_ctrldev_init(void)
> >> +{
> >> +	int ret;
> >> +
> >> +	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl");
> >> +	if (ret < 0) {
> >> +		pr_err("rpmsg: failed to allocate char dev region\n");
> >> +		return ret;
> >> +	}
> >> +
> >> +	rpmsg_class = class_create(THIS_MODULE, "rpmsg");
> > 
> > This class thing really bothers me.  Keeping this here means that rpmsg_eptdevs
> > created from user space will be associated to this rpmsg_class but those created
> > from the name service won't.  As such I propose to move this to rpmsg_char and
> > simply not associate the control device to the class.
> > 
> > Otherwise we'd have to introduce some mechanic only to deal with the creation of
> > the class and I don't think it is worth.  We can revise that approach if someone
> > complains we broke their user space. 
> 
> I agree with that as it was my first proposed approach here [1]

Yeah, sorry about that.  This patch review process is not an exact science...

> 
> [1] https://www.spinics.net/lists/linux-arm-msm/msg81194.html
> 
> Thanks,
> Arnaud
> 
> > 
> > 
> >> +	if (IS_ERR(rpmsg_class)) {
> >> +		pr_err("failed to create rpmsg class\n");
> >> +		ret = PTR_ERR(rpmsg_class);
> >> +		goto free_region;
> >> +	}
> >> +
> >> +	ret = register_rpmsg_driver(&rpmsg_ctrldev_driver);
> >> +	if (ret < 0) {
> >> +		pr_err("rpmsg ctrl: failed to register rpmsg driver\n");
> >> +		goto free_class;
> >> +	}
> >> +
> >> +	return 0;
> >> +
> >> +free_class:
> >> +	class_destroy(rpmsg_class);
> >> +free_region:
> >> +	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
> >> +
> >> +	return ret;
> >> +}
> >> +postcore_initcall(rpmsg_ctrldev_init);
> >> +
> >> +static void rpmsg_ctrldev_exit(void)
> >> +{
> >> +	unregister_rpmsg_driver(&rpmsg_ctrldev_driver);
> >> +	class_destroy(rpmsg_class);
> >> +	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
> >> +}
> >> +module_exit(rpmsg_ctrldev_exit);
> >> +
> >> +MODULE_DESCRIPTION("rpmsg control interface");
> >> +MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
> >> +MODULE_LICENSE("GPL v2");
> >> -- 
> >> 2.17.1
> >>
Arnaud POULIQUEN April 22, 2021, 4:41 p.m. UTC | #4
On 4/22/21 6:32 PM, Mathieu Poirier wrote:
> On Thu, Apr 22, 2021 at 09:56:41AM +0200, Arnaud POULIQUEN wrote:
>>
>>
>> On 4/21/21 8:04 PM, Mathieu Poirier wrote:
>>> On Tue, Apr 13, 2021 at 03:44:53PM +0200, Arnaud Pouliquen wrote:
>>>> Create the rpmsg_ctrl.c module and move the code related to the
>>>> rpmsg_ctrldev device in this new module.
>>>>
>>>> Add the dependency between rpmsg_char and rpmsg_ctrl in the
>>>> kconfig file.
>>>>
>>>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
>>>> ---
>>>> update from v1:
>>>> - keep "rpmsg_chrdev" driver name in rpmsg_ctrl, driver will be renamed
>>>>   in next path that renames the rpmsg_chrdev_create_eptdev.
>>>> - rename the chardev regions
>>>> - move RPMSG_DEV_MAX to rpmsg_char.h
>>>> ---
>>>>  drivers/rpmsg/Kconfig      |   9 ++
>>>>  drivers/rpmsg/Makefile     |   1 +
>>>>  drivers/rpmsg/rpmsg_char.c | 181 +----------------------------
>>>>  drivers/rpmsg/rpmsg_char.h |   2 +
>>>>  drivers/rpmsg/rpmsg_ctrl.c | 231 +++++++++++++++++++++++++++++++++++++
>>>>  5 files changed, 245 insertions(+), 179 deletions(-)
>>>>  create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
>>>>
>>>> diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
>>>> index 0b4407abdf13..d822ec9ec692 100644
>>>> --- a/drivers/rpmsg/Kconfig
>>
>> snip[...]
>>
>>>> +static int rpmsg_ctrldev_init(void)
>>>> +{
>>>> +	int ret;
>>>> +
>>>> +	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl");
>>>> +	if (ret < 0) {
>>>> +		pr_err("rpmsg: failed to allocate char dev region\n");
>>>> +		return ret;
>>>> +	}
>>>> +
>>>> +	rpmsg_class = class_create(THIS_MODULE, "rpmsg");
>>>
>>> This class thing really bothers me.  Keeping this here means that rpmsg_eptdevs
>>> created from user space will be associated to this rpmsg_class but those created
>>> from the name service won't.  As such I propose to move this to rpmsg_char and
>>> simply not associate the control device to the class.
>>>
>>> Otherwise we'd have to introduce some mechanic only to deal with the creation of
>>> the class and I don't think it is worth.  We can revise that approach if someone
>>> complains we broke their user space. 
>>
>> I agree with that as it was my first proposed approach here [1]
> 
> Yeah, sorry about that.  This patch review process is not an exact science...

No worries, exploring alternatives is part of the upstream process  :)

> 
>>
>> [1] https://www.spinics.net/lists/linux-arm-msm/msg81194.html
>>
>> Thanks,
>> Arnaud
>>
>>>
>>>
>>>> +	if (IS_ERR(rpmsg_class)) {
>>>> +		pr_err("failed to create rpmsg class\n");
>>>> +		ret = PTR_ERR(rpmsg_class);
>>>> +		goto free_region;
>>>> +	}
>>>> +
>>>> +	ret = register_rpmsg_driver(&rpmsg_ctrldev_driver);
>>>> +	if (ret < 0) {
>>>> +		pr_err("rpmsg ctrl: failed to register rpmsg driver\n");
>>>> +		goto free_class;
>>>> +	}
>>>> +
>>>> +	return 0;
>>>> +
>>>> +free_class:
>>>> +	class_destroy(rpmsg_class);
>>>> +free_region:
>>>> +	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
>>>> +
>>>> +	return ret;
>>>> +}
>>>> +postcore_initcall(rpmsg_ctrldev_init);
>>>> +
>>>> +static void rpmsg_ctrldev_exit(void)
>>>> +{
>>>> +	unregister_rpmsg_driver(&rpmsg_ctrldev_driver);
>>>> +	class_destroy(rpmsg_class);
>>>> +	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
>>>> +}
>>>> +module_exit(rpmsg_ctrldev_exit);
>>>> +
>>>> +MODULE_DESCRIPTION("rpmsg control interface");
>>>> +MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
>>>> +MODULE_LICENSE("GPL v2");
>>>> -- 
>>>> 2.17.1
>>>>
diff mbox series

Patch

diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
index 0b4407abdf13..d822ec9ec692 100644
--- a/drivers/rpmsg/Kconfig
+++ b/drivers/rpmsg/Kconfig
@@ -10,11 +10,20 @@  config RPMSG_CHAR
 	tristate "RPMSG device interface"
 	depends on RPMSG
 	depends on NET
+	select RPMSG_CTRL
 	help
 	  Say Y here to export rpmsg endpoints as device files, usually found
 	  in /dev. They make it possible for user-space programs to send and
 	  receive rpmsg packets.
 
+config RPMSG_CTRL
+	tristate "RPMSG control interface"
+	depends on RPMSG
+	help
+	  Say Y here to enable the support of the /dev/rpmsg_ctrlX API. This API
+	  allows user-space programs to create endpoints with specific service name,
+	  source and destination addresses.
+
 config RPMSG_NS
 	tristate "RPMSG name service announcement"
 	depends on RPMSG
diff --git a/drivers/rpmsg/Makefile b/drivers/rpmsg/Makefile
index 8d452656f0ee..58e3b382e316 100644
--- a/drivers/rpmsg/Makefile
+++ b/drivers/rpmsg/Makefile
@@ -1,6 +1,7 @@ 
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_RPMSG)		+= rpmsg_core.o
 obj-$(CONFIG_RPMSG_CHAR)	+= rpmsg_char.o
+obj-$(CONFIG_RPMSG_CTRL)	+= rpmsg_ctrl.o
 obj-$(CONFIG_RPMSG_NS)		+= rpmsg_ns.o
 obj-$(CONFIG_RPMSG_MTK_SCP)	+= mtk_rpmsg.o
 qcom_glink-objs			:= qcom_glink_native.o qcom_glink_ssr.o
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index b9df8dc4365f..21ef9d9eccd7 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -26,33 +26,14 @@ 
 #include "rpmsg_char.h"
 #include "rpmsg_internal.h"
 
-#define RPMSG_DEV_MAX	(MINORMASK + 1)
-
 static dev_t rpmsg_major;
-static struct class *rpmsg_class;
 
-static DEFINE_IDA(rpmsg_ctrl_ida);
 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)
 
-#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev)
-#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev)
-
-/**
- * struct rpmsg_ctrldev - control device for instantiating endpoint devices
- * @rpdev:	underlaying rpmsg device
- * @cdev:	cdev for the ctrl device
- * @dev:	device for the ctrl device
- */
-struct rpmsg_ctrldev {
-	struct rpmsg_device *rpdev;
-	struct cdev cdev;
-	struct device dev;
-};
-
 /**
  * struct rpmsg_eptdev - endpoint device context
  * @dev:	endpoint device
@@ -409,169 +390,13 @@  int rpmsg_chrdev_create_eptdev(struct rpmsg_device *rpdev, struct device *parent
 }
 EXPORT_SYMBOL(rpmsg_chrdev_create_eptdev);
 
-static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp)
-{
-	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
-
-	get_device(&ctrldev->dev);
-	filp->private_data = ctrldev;
-
-	return 0;
-}
-
-static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp)
-{
-	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
-
-	put_device(&ctrldev->dev);
-
-	return 0;
-}
-
-static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd,
-				unsigned long arg)
-{
-	struct rpmsg_ctrldev *ctrldev = fp->private_data;
-	void __user *argp = (void __user *)arg;
-	struct rpmsg_endpoint_info eptinfo;
-	struct rpmsg_channel_info chinfo;
-
-	if (cmd != RPMSG_CREATE_EPT_IOCTL)
-		return -EINVAL;
-
-	if (copy_from_user(&eptinfo, argp, sizeof(eptinfo)))
-		return -EFAULT;
-
-	memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE);
-	chinfo.name[RPMSG_NAME_SIZE-1] = '\0';
-	chinfo.src = eptinfo.src;
-	chinfo.dst = eptinfo.dst;
-
-	return rpmsg_chrdev_create_eptdev(ctrldev->rpdev, &ctrldev->dev, chinfo, rpmsg_class);
-};
-
-static const struct file_operations rpmsg_ctrldev_fops = {
-	.owner = THIS_MODULE,
-	.open = rpmsg_ctrldev_open,
-	.release = rpmsg_ctrldev_release,
-	.unlocked_ioctl = rpmsg_ctrldev_ioctl,
-	.compat_ioctl = compat_ptr_ioctl,
-};
-
-static void rpmsg_ctrldev_release_device(struct device *dev)
-{
-	struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev);
-
-	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
-	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
-	cdev_del(&ctrldev->cdev);
-	kfree(ctrldev);
-}
-
-static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
-{
-	struct rpmsg_ctrldev *ctrldev;
-	struct device *dev;
-	int ret;
-
-	ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL);
-	if (!ctrldev)
-		return -ENOMEM;
-
-	ctrldev->rpdev = rpdev;
-
-	dev = &ctrldev->dev;
-	device_initialize(dev);
-	dev->parent = &rpdev->dev;
-	dev->class = rpmsg_class;
-
-	cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
-	ctrldev->cdev.owner = THIS_MODULE;
-
-	ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
-	if (ret < 0)
-		goto free_ctrldev;
-	dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
-
-	ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL);
-	if (ret < 0)
-		goto free_minor_ida;
-	dev->id = ret;
-	dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret);
-
-	ret = cdev_add(&ctrldev->cdev, dev->devt, 1);
-	if (ret)
-		goto free_ctrl_ida;
-
-	/* We can now rely on the release function for cleanup */
-	dev->release = rpmsg_ctrldev_release_device;
-
-	ret = device_add(dev);
-	if (ret) {
-		dev_err(&rpdev->dev, "device_add failed: %d\n", ret);
-		put_device(dev);
-	}
-
-	dev_set_drvdata(&rpdev->dev, ctrldev);
-
-	return ret;
-
-free_ctrl_ida:
-	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
-free_minor_ida:
-	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
-free_ctrldev:
-	put_device(dev);
-	kfree(ctrldev);
-
-	return ret;
-}
-
-static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
-{
-	struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev);
-	int ret;
-
-	/* Destroy all endpoints */
-	ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_chrdev_destroy_eptdev);
-	if (ret)
-		dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
-
-	device_del(&ctrldev->dev);
-	put_device(&ctrldev->dev);
-}
-
-static struct rpmsg_driver rpmsg_chrdev_driver = {
-	.probe = rpmsg_chrdev_probe,
-	.remove = rpmsg_chrdev_remove,
-	.drv = {
-		.name = "rpmsg_chrdev",
-	},
-};
-
 static int rpmsg_chrdev_init(void)
 {
 	int ret;
 
-	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg");
-	if (ret < 0) {
+	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_char");
+	if (ret < 0)
 		pr_err("rpmsg: failed to allocate char dev region\n");
-		return ret;
-	}
-
-	rpmsg_class = class_create(THIS_MODULE, "rpmsg");
-	if (IS_ERR(rpmsg_class)) {
-		pr_err("failed to create rpmsg class\n");
-		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
-		return PTR_ERR(rpmsg_class);
-	}
-
-	ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
-	if (ret < 0) {
-		pr_err("rpmsgchr: failed to register rpmsg driver\n");
-		class_destroy(rpmsg_class);
-		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
-	}
 
 	return ret;
 }
@@ -579,8 +404,6 @@  postcore_initcall(rpmsg_chrdev_init);
 
 static void rpmsg_chrdev_exit(void)
 {
-	unregister_rpmsg_driver(&rpmsg_chrdev_driver);
-	class_destroy(rpmsg_class);
 	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
 }
 module_exit(rpmsg_chrdev_exit);
diff --git a/drivers/rpmsg/rpmsg_char.h b/drivers/rpmsg/rpmsg_char.h
index 379d2ae2bee8..f20a215073c3 100644
--- a/drivers/rpmsg/rpmsg_char.h
+++ b/drivers/rpmsg/rpmsg_char.h
@@ -6,6 +6,8 @@ 
 #ifndef __RPMSG_CHRDEV_H__
 #define __RPMSG_CHRDEV_H__
 
+#define RPMSG_DEV_MAX	(MINORMASK + 1)
+
 #if IS_REACHABLE(CONFIG_RPMSG_CHAR)
 /**
  * rpmsg_chrdev_create_eptdev() - register char device based on an endpoint
diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
new file mode 100644
index 000000000000..a5bb9ed97f32
--- /dev/null
+++ b/drivers/rpmsg/rpmsg_ctrl.c
@@ -0,0 +1,231 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021, 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.
+ */
+#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/rpmsg.h>
+#include <linux/slab.h>
+#include <uapi/linux/rpmsg.h>
+
+#include "rpmsg_char.h"
+#include "rpmsg_internal.h"
+
+static dev_t rpmsg_major;
+struct class *rpmsg_class;
+
+static DEFINE_IDA(rpmsg_ctrl_ida);
+static DEFINE_IDA(rpmsg_minor_ida);
+
+#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev)
+#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev)
+
+/**
+ * struct rpmsg_ctrldev - control device for instantiating endpoint devices
+ * @rpdev:	underlaying rpmsg device
+ * @cdev:	cdev for the ctrl device
+ * @dev:	device for the ctrl device
+ */
+struct rpmsg_ctrldev {
+	struct rpmsg_device *rpdev;
+	struct cdev cdev;
+	struct device dev;
+};
+
+static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp)
+{
+	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
+
+	get_device(&ctrldev->dev);
+	filp->private_data = ctrldev;
+
+	return 0;
+}
+
+static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp)
+{
+	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);
+
+	put_device(&ctrldev->dev);
+
+	return 0;
+}
+
+static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd,
+				unsigned long arg)
+{
+	struct rpmsg_ctrldev *ctrldev = fp->private_data;
+	void __user *argp = (void __user *)arg;
+	struct rpmsg_endpoint_info eptinfo;
+	struct rpmsg_channel_info chinfo;
+
+	if (cmd != RPMSG_CREATE_EPT_IOCTL)
+		return -EINVAL;
+
+	if (copy_from_user(&eptinfo, argp, sizeof(eptinfo)))
+		return -EFAULT;
+
+	memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE);
+	chinfo.name[RPMSG_NAME_SIZE - 1] = '\0';
+	chinfo.src = eptinfo.src;
+	chinfo.dst = eptinfo.dst;
+
+	return rpmsg_chrdev_create_eptdev(ctrldev->rpdev, &ctrldev->dev, chinfo, rpmsg_class);
+};
+
+static const struct file_operations rpmsg_ctrldev_fops = {
+	.owner = THIS_MODULE,
+	.open = rpmsg_ctrldev_open,
+	.release = rpmsg_ctrldev_release,
+	.unlocked_ioctl = rpmsg_ctrldev_ioctl,
+	.compat_ioctl = compat_ptr_ioctl,
+};
+
+static void rpmsg_ctrldev_release_device(struct device *dev)
+{
+	struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev);
+
+	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
+	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
+	cdev_del(&ctrldev->cdev);
+	kfree(ctrldev);
+}
+
+static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev)
+{
+	struct rpmsg_ctrldev *ctrldev;
+	struct device *dev;
+	int ret;
+
+	ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL);
+	if (!ctrldev)
+		return -ENOMEM;
+
+	ctrldev->rpdev = rpdev;
+
+	dev = &ctrldev->dev;
+	device_initialize(dev);
+	dev->parent = &rpdev->dev;
+	dev->class = rpmsg_class;
+
+	cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
+	ctrldev->cdev.owner = THIS_MODULE;
+
+	ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
+	if (ret < 0)
+		goto free_ctrldev;
+	dev->devt = MKDEV(MAJOR(rpmsg_major), ret);
+
+	ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL);
+	if (ret < 0)
+		goto free_minor_ida;
+	dev->id = ret;
+	dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret);
+
+	ret = cdev_add(&ctrldev->cdev, dev->devt, 1);
+	if (ret)
+		goto free_ctrl_ida;
+
+	/* We can now rely on the release function for cleanup */
+	dev->release = rpmsg_ctrldev_release_device;
+
+	ret = device_add(dev);
+	if (ret) {
+		dev_err(&rpdev->dev, "device_add failed: %d\n", ret);
+		put_device(dev);
+	}
+
+	dev_set_drvdata(&rpdev->dev, ctrldev);
+
+	return ret;
+
+free_ctrl_ida:
+	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
+free_minor_ida:
+	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
+free_ctrldev:
+	put_device(dev);
+	kfree(ctrldev);
+
+	return ret;
+}
+
+static void rpmsg_ctrldev_remove(struct rpmsg_device *rpdev)
+{
+	struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev);
+	int ret;
+
+	/* Destroy all endpoints */
+	ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_chrdev_destroy_eptdev);
+	if (ret)
+		dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
+
+	device_del(&ctrldev->dev);
+	put_device(&ctrldev->dev);
+}
+
+static struct rpmsg_driver rpmsg_ctrldev_driver = {
+	.probe = rpmsg_ctrldev_probe,
+	.remove = rpmsg_ctrldev_remove,
+	.drv = {
+		.name = "rpmsg_chrdev",
+	},
+};
+
+static int rpmsg_ctrldev_init(void)
+{
+	int ret;
+
+	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl");
+	if (ret < 0) {
+		pr_err("rpmsg: failed to allocate char dev region\n");
+		return ret;
+	}
+
+	rpmsg_class = class_create(THIS_MODULE, "rpmsg");
+	if (IS_ERR(rpmsg_class)) {
+		pr_err("failed to create rpmsg class\n");
+		ret = PTR_ERR(rpmsg_class);
+		goto free_region;
+	}
+
+	ret = register_rpmsg_driver(&rpmsg_ctrldev_driver);
+	if (ret < 0) {
+		pr_err("rpmsg ctrl: failed to register rpmsg driver\n");
+		goto free_class;
+	}
+
+	return 0;
+
+free_class:
+	class_destroy(rpmsg_class);
+free_region:
+	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+
+	return ret;
+}
+postcore_initcall(rpmsg_ctrldev_init);
+
+static void rpmsg_ctrldev_exit(void)
+{
+	unregister_rpmsg_driver(&rpmsg_ctrldev_driver);
+	class_destroy(rpmsg_class);
+	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+}
+module_exit(rpmsg_ctrldev_exit);
+
+MODULE_DESCRIPTION("rpmsg control interface");
+MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
+MODULE_LICENSE("GPL v2");