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Subject: Re: [PATCH v5 06/16] rpmsg: move the rpmsg control device from
 rpmsg_char to rpmsg_ctrl
To:     Mathieu Poirier <mathieu.poirier@linaro.org>
CC:     Bjorn Andersson <bjorn.andersson@linaro.org>,
        Ohad Ben-Cohen <ohad@wizery.com>,
        Andy Gross <agross@kernel.org>,
        <linux-remoteproc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-stm32@st-md-mailman.stormreply.com>,
        <linux-arm-msm@vger.kernel.org>
References: <20210219111501.14261-1-arnaud.pouliquen@foss.st.com>
 <20210219111501.14261-7-arnaud.pouliquen@foss.st.com>
 <20210302183516.GC3791957@xps15>
From:   Arnaud POULIQUEN <arnaud.pouliquen@foss.st.com>
Message-ID: <64760ba3-5b23-bf74-6961-b77813919abc@foss.st.com>
Date:   Wed, 3 Mar 2021 15:59:34 +0100
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On 3/2/21 7:35 PM, Mathieu Poirier wrote:
> On Fri, Feb 19, 2021 at 12:14:51PM +0100, Arnaud Pouliquen wrote:
>> Move the code related to the rpmsg_ctrl char device to the new
>> rpmsg_ctrl.c module.
>> Manage the dependency in the kconfig.
>>
>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
>> ---
>>  drivers/rpmsg/Kconfig      |   9 ++
>>  drivers/rpmsg/Makefile     |   1 +
>>  drivers/rpmsg/rpmsg_char.c | 163 ----------------------------
>>  drivers/rpmsg/rpmsg_ctrl.c | 216 +++++++++++++++++++++++++++++++++++++
>>  4 files changed, 226 insertions(+), 163 deletions(-)
>>  create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
>>
>> diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
>> index 0b4407abdf13..2d0cd7fdd710 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_ctlX API. This API
> 
> s/rpmsg_ctlX/rpmsg_ctrlX

Good catch!

> 
>> +	  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 23e369a00531..83c10b39b139 100644
>> --- a/drivers/rpmsg/rpmsg_char.c
>> +++ b/drivers/rpmsg/rpmsg_char.c
>> @@ -31,28 +31,12 @@
>>  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;
>> -};
> 
> This showed up in rpmsg_ctrl.c as rpmsg_ctrl.  The same goes for many functions
> names - they are removed here and re-introduced under a different name, which
> makes it very hard to follow.  What ends up in the new file should be a carbon
> copy of what was moved.

Ok i will split it in 2 steps.

Thanks
Arnaud

> 
> I'm out of time for today, more comments tomorrow.
> 
> Thanks,
> Mathieu
> 
>> -
>>  /**
>>   * struct rpmsg_eptdev - endpoint device context
>>   * @dev:	endpoint device
>> @@ -411,145 +395,6 @@ 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);
>> -};
>> -
>> -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;
>> -
>> -	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_eptdev_destroy);
>> -	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;
>> @@ -567,20 +412,12 @@ static int rpmsg_chrdev_init(void)
>>  		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;
>>  }
>>  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);
>>  }
>> diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
>> new file mode 100644
>> index 000000000000..fa05b67d24da
>> --- /dev/null
>> +++ b/drivers/rpmsg/rpmsg_ctrl.c
>> @@ -0,0 +1,216 @@
>> +// 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"
>> +
>> +#define RPMSG_DEV_MAX	(MINORMASK + 1)
>> +
>> +static dev_t rpmsg_major;
>> +
>> +static DEFINE_IDA(rpmsg_ctrl_ida);
>> +static DEFINE_IDA(rpmsg_minor_ida);
>> +
>> +#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrl, dev)
>> +#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrl, cdev)
>> +
>> +/**
>> + * struct rpmsg_ctrl - control device for instantiating endpoint devices
>> + * @rpdev:	underlaying rpmsg device
>> + * @cdev:	cdev for the ctrl device
>> + * @dev:	device for the ctrl device
>> + */
>> +struct rpmsg_ctrl {
>> +	struct rpmsg_device *rpdev;
>> +	struct cdev cdev;
>> +	struct device dev;
>> +};
>> +
>> +static int rpmsg_ctrl_open(struct inode *inode, struct file *filp)
>> +{
>> +	struct rpmsg_ctrl *ctrldev = cdev_to_ctrldev(inode->i_cdev);
>> +
>> +	get_device(&ctrldev->dev);
>> +	filp->private_data = ctrldev;
>> +
>> +	return 0;
>> +}
>> +
>> +static int rpmsg_ctrl_release(struct inode *inode, struct file *filp)
>> +{
>> +	struct rpmsg_ctrl *ctrldev = cdev_to_ctrldev(inode->i_cdev);
>> +
>> +	put_device(&ctrldev->dev);
>> +
>> +	return 0;
>> +}
>> +
>> +static long rpmsg_ctrl_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
>> +{
>> +	struct rpmsg_ctrl *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);
>> +};
>> +
>> +static const struct file_operations rpmsg_ctrl_fops = {
>> +	.owner = THIS_MODULE,
>> +	.open = rpmsg_ctrl_open,
>> +	.release = rpmsg_ctrl_release,
>> +	.unlocked_ioctl = rpmsg_ctrl_ioctl,
>> +	.compat_ioctl = compat_ptr_ioctl,
>> +};
>> +
>> +static void rpmsg_ctrl_release_device(struct device *dev)
>> +{
>> +	struct rpmsg_ctrl *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_ctrl_probe(struct rpmsg_device *rpdev)
>> +{
>> +	struct rpmsg_ctrl *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;
>> +
>> +	cdev_init(&ctrldev->cdev, &rpmsg_ctrl_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_ctrl_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_ctrl_remove(struct rpmsg_device *rpdev)
>> +{
>> +	struct rpmsg_ctrl *ctrldev = dev_get_drvdata(&rpdev->dev);
>> +	int ret;
>> +
>> +	/* Destroy all endpoints */
>> +	ret = device_for_each_child(&ctrldev->dev, NULL,
>> +				    rpmsg_chrdev_eptdev_destroy);
>> +	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_ctrl_driver = {
>> +	.probe = rpmsg_ctrl_probe,
>> +	.remove = rpmsg_ctrl_remove,
>> +	.drv = {
>> +		.name = "rpmsg_chrdev",
>> +	},
>> +};
>> +
>> +static int rpmsg_ctrl_init(void)
>> +{
>> +	int ret;
>> +
>> +	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg");
>> +	if (ret < 0) {
>> +		pr_err("rpmsg: failed to allocate char dev region\n");
>> +		return ret;
>> +	}
>> +
>> +	ret = register_rpmsg_driver(&rpmsg_ctrl_driver);
>> +	if (ret < 0) {
>> +		pr_err("rpmsg ctrl: failed to register rpmsg driver\n");
>> +		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
>> +	}
>> +
>> +	return ret;
>> +}
>> +postcore_initcall(rpmsg_ctrl_init);
>> +
>> +static void rpmsg_ctrl_exit(void)
>> +{
>> +	unregister_rpmsg_driver(&rpmsg_ctrl_driver);
>> +	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
>> +}
>> +module_exit(rpmsg_ctrl_exit);
>> +
>> +MODULE_DESCRIPTION("rpmsg control interface");
>> +MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
>> +MODULE_LICENSE("GPL v2");
>> -- 
>> 2.17.1
>>