Re: [PATCH v5 06/16] rpmsg: move the rpmsg control device from rpmsg_char to rpmsg_ctrl

[Mathieu Poirier <mathieu.poirier@linaro.org>]

On Wed, Mar 03, 2021 at 03:59:34PM +0100, Arnaud POULIQUEN wrote:
> 
> 
> 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.

In most cases I don't think there is a need for a wholesale renaming exercise.
To me having a struct rpmsg_ctrldev and functions names such as
rpmsg_ctrldev_open() in a file called rpmsg_ctrl.c is perfectly acceptable.

> 
> 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
> >>