On Fri, May 09, 2025 at 11:59:26PM +0800, Dawei Li wrote:
> Introduce new eptdev abstraction based on anon inode. The new API is
> exactly same with legacy one except:
>
> - It's anonymous and devnode/path free.
> - Its fops->open() is empty.
>
> Signed-off-by: Dawei Li <[email protected]>
> ---
> drivers/rpmsg/rpmsg_char.c | 44 ++++++++++++++++++++++++++++++++++++++
> drivers/rpmsg/rpmsg_char.h | 19 ++++++++++++++++
> 2 files changed, 63 insertions(+)
>
> diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
> index 5b2a883d6236..b0ec05f88013 100644
> --- a/drivers/rpmsg/rpmsg_char.c
> +++ b/drivers/rpmsg/rpmsg_char.c
> @@ -13,6 +13,7 @@
>
> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>
> +#include <linux/anon_inodes.h>
> #include <linux/cdev.h>
> #include <linux/device.h>
> #include <linux/fs.h>
> @@ -517,6 +518,49 @@ int rpmsg_chrdev_eptdev_create(struct rpmsg_device
> *rpdev, struct device *parent
> }
> EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create);
>
> +static const struct file_operations rpmsg_eptdev_anon_fops = {
> + .owner = THIS_MODULE,
> + .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,
> +};
> +
> +int rpmsg_eptdev_create(struct rpmsg_device *rpdev, struct device *parent,
> + struct rpmsg_channel_info chinfo, int *pfd)
rpmsg_anonymous_eptdev_create()
> +{
> + struct rpmsg_eptdev *eptdev;
> + int ret, fd;
> +
> + eptdev = __rpmsg_chrdev_eptdev_alloc(rpdev, parent, false);
> + if (IS_ERR(eptdev))
> + return PTR_ERR(eptdev);
> +
> + ret = __rpmsg_chrdev_eptdev_add(eptdev, chinfo, false);
> + if (ret) {
> + dev_err(&eptdev->dev, "failed to add %s\n",
> eptdev->chinfo.name);
> + return ret;
> + }
> +
> + fd = anon_inode_getfd("rpmsg-eptdev", &rpmsg_eptdev_anon_fops, eptdev,
> O_RDWR | O_CLOEXEC);
> + if (fd < 0) {
> + put_device(&eptdev->dev);
> + return fd;
> + }
> +
> + mutex_lock(&eptdev->ept_lock);
> + ret = __rpmsg_eptdev_open(eptdev);
> + mutex_unlock(&eptdev->ept_lock);
> +
> + if (!ret)
> + *pfd = fd;
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(rpmsg_eptdev_create);
> +
> static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
> {
> struct rpmsg_channel_info chinfo;
> diff --git a/drivers/rpmsg/rpmsg_char.h b/drivers/rpmsg/rpmsg_char.h
> index 117d9cbc52f0..8cc2c14537da 100644
> --- a/drivers/rpmsg/rpmsg_char.h
> +++ b/drivers/rpmsg/rpmsg_char.h
> @@ -19,6 +19,19 @@
> int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device
> *parent,
> struct rpmsg_channel_info chinfo);
>
> +/**
> + * rpmsg_eptdev_create() - register ep device and its associated fd based on
> an endpoint
> + * @rpdev: prepared rpdev to be used for creating endpoints
> + * @parent: parent device
> + * @chinfo: associated endpoint channel information.
> + * @pfd: fd in represent of endpoint device
> + *
> + * This function create a new rpmsg endpoint device and its associated fd to
> instantiate a new
> + * endpoint based on chinfo information.
> + */
> +int rpmsg_eptdev_create(struct rpmsg_device *rpdev, struct device *parent,
> + struct rpmsg_channel_info chinfo, int *pfd);
> +
> /**
> * rpmsg_chrdev_eptdev_destroy() - destroy created char device endpoint.
> * @data: private data associated to the endpoint device
> @@ -36,6 +49,12 @@ static inline int rpmsg_chrdev_eptdev_create(struct
> rpmsg_device *rpdev, struct
> return -ENXIO;
> }
>
> +static inline int rpmsg_eptdev_create(struct rpmsg_device *rpdev, struct
> device *parent,
> + struct rpmsg_channel_info chinfo, int
> *pfd)
> +{
> + return -ENXIO;
> +}
> +
> static inline int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data)
> {
> return -ENXIO;
> --
> 2.25.1
>
