[PATCH 30/34] vfio/mdev: Remove vfio_mdev.c

From: Christoph Hellwig
Date: Mon Apr 11 2022 - 10:17:27 EST

From: Jason Gunthorpe <jgg@xxxxxxxxxx>

Now that all mdev drivers directly create their own mdev_device driver and
directly register with the vfio core's vfio_device_ops this is all dead
code.

Delete vfio_mdev.c and the mdev_parent_ops members that are connected to
it.

Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
.../driver-api/vfio-mediated-device.rst | 3 -
drivers/vfio/mdev/Makefile | 2 +-
drivers/vfio/mdev/mdev_core.c | 40 +----
drivers/vfio/mdev/mdev_driver.c | 10 --
drivers/vfio/mdev/mdev_private.h | 2 -
drivers/vfio/mdev/vfio_mdev.c | 152 ------------------
include/linux/mdev.h | 48 +-----
7 files changed, 6 insertions(+), 251 deletions(-)
delete mode 100644 drivers/vfio/mdev/vfio_mdev.c

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index 9f26079cacae3..5a6e18a651a18 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -138,9 +138,6 @@ The structures in the mdev_parent_ops structure are as follows:
* supported_config: attributes to define supported configurations
* device_driver: device driver to bind for mediated device instances

-The mdev_parent_ops also still has various functions pointers. Theses exist
-for historical reasons only and shall not be used for new drivers.
-
When a driver wants to add the GUID creation sysfs to an existing device it has
probe'd to then it should call::

diff --git a/drivers/vfio/mdev/Makefile b/drivers/vfio/mdev/Makefile
index ff9ecd8021250..7c236ba1b90eb 100644
--- a/drivers/vfio/mdev/Makefile
+++ b/drivers/vfio/mdev/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only

-mdev-y := mdev_core.o mdev_sysfs.o mdev_driver.o vfio_mdev.o
+mdev-y := mdev_core.o mdev_sysfs.o mdev_driver.o

obj-$(CONFIG_VFIO_MDEV) += mdev.o
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index b314101237fe2..8b1e86b9e8bc0 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -89,17 +89,10 @@ void mdev_release_parent(struct kref *kref)
static void mdev_device_remove_common(struct mdev_device *mdev)
{
struct mdev_parent *parent = mdev->type->parent;
- int ret;

mdev_remove_sysfs_files(mdev);
device_del(&mdev->dev);
lockdep_assert_held(&parent->unreg_sem);
- if (parent->ops->remove) {
- ret = parent->ops->remove(mdev);
- if (ret)
- dev_err(&mdev->dev, "Remove failed: err=%d\n", ret);
- }
-
/* Balances with device_initialize() */
put_device(&mdev->dev);
}
@@ -131,7 +124,7 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
/* check for mandatory ops */
if (!ops || !ops->supported_type_groups)
return -EINVAL;
- if (!ops->device_driver && (!ops->create || !ops->remove))
+ if (!ops->device_driver)
return -EINVAL;

dev = get_device(dev);
@@ -297,18 +290,10 @@ int mdev_device_create(struct mdev_type *type, const guid_t *uuid)
goto out_put_device;
}

- if (parent->ops->create) {
- ret = parent->ops->create(mdev);
- if (ret)
- goto out_unlock;
- }
-
ret = device_add(&mdev->dev);
if (ret)
- goto out_remove;
+ goto out_unlock;

- if (!drv)
- drv = &vfio_mdev_driver;
ret = device_driver_attach(&drv->driver, &mdev->dev);
if (ret)
goto out_del;
@@ -325,9 +310,6 @@ int mdev_device_create(struct mdev_type *type, const guid_t *uuid)

out_del:
device_del(&mdev->dev);
-out_remove:
- if (parent->ops->remove)
- parent->ops->remove(mdev);
out_unlock:
up_read(&parent->unreg_sem);
out_put_device:
@@ -370,28 +352,14 @@ int mdev_device_remove(struct mdev_device *mdev)

static int __init mdev_init(void)
{
- int rc;
-
- rc = mdev_bus_register();
- if (rc)
- return rc;
- rc = mdev_register_driver(&vfio_mdev_driver);
- if (rc)
- goto err_bus;
- return 0;
-err_bus:
- mdev_bus_unregister();
- return rc;
+ return bus_register(&mdev_bus_type);
}

static void __exit mdev_exit(void)
{
- mdev_unregister_driver(&vfio_mdev_driver);
-
if (mdev_bus_compat_class)
class_compat_unregister(mdev_bus_compat_class);
-
- mdev_bus_unregister();
+ bus_unregister(&mdev_bus_type);
}

subsys_initcall(mdev_init)
diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
index 7927ed4f1711f..9c2af59809e2e 100644
--- a/drivers/vfio/mdev/mdev_driver.c
+++ b/drivers/vfio/mdev/mdev_driver.c
@@ -74,13 +74,3 @@ void mdev_unregister_driver(struct mdev_driver *drv)
driver_unregister(&drv->driver);
}
EXPORT_SYMBOL(mdev_unregister_driver);
-
-int mdev_bus_register(void)
-{
- return bus_register(&mdev_bus_type);
-}
-
-void mdev_bus_unregister(void)
-{
- bus_unregister(&mdev_bus_type);
-}
diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
index afbad7b0a14a1..6999c89db7b16 100644
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -37,8 +37,6 @@ struct mdev_type {
#define to_mdev_type(_kobj) \
container_of(_kobj, struct mdev_type, kobj)

-extern struct mdev_driver vfio_mdev_driver;
-
int parent_create_sysfs_files(struct mdev_parent *parent);
void parent_remove_sysfs_files(struct mdev_parent *parent);

diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
deleted file mode 100644
index a90e24b0c851d..0000000000000
--- a/drivers/vfio/mdev/vfio_mdev.c
+++ /dev/null
@@ -1,152 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * VFIO based driver for Mediated device
- *
- * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
- * Author: Neo Jia <cjia@xxxxxxxxxx>
- * Kirti Wankhede <kwankhede@xxxxxxxxxx>
- */
-
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/kernel.h>
-#include <linux/slab.h>
-#include <linux/vfio.h>
-#include <linux/mdev.h>
-
-#include "mdev_private.h"
-
-static int vfio_mdev_open_device(struct vfio_device *core_vdev)
-{
- struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
- struct mdev_parent *parent = mdev->type->parent;
-
- if (unlikely(!parent->ops->open_device))
- return 0;
-
- return parent->ops->open_device(mdev);
-}
-
-static void vfio_mdev_close_device(struct vfio_device *core_vdev)
-{
- struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
- struct mdev_parent *parent = mdev->type->parent;
-
- if (likely(parent->ops->close_device))
- parent->ops->close_device(mdev);
-}
-
-static long vfio_mdev_unlocked_ioctl(struct vfio_device *core_vdev,
- unsigned int cmd, unsigned long arg)
-{
- struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
- struct mdev_parent *parent = mdev->type->parent;
-
- if (unlikely(!parent->ops->ioctl))
- return 0;
-
- return parent->ops->ioctl(mdev, cmd, arg);
-}
-
-static ssize_t vfio_mdev_read(struct vfio_device *core_vdev, char __user *buf,
- size_t count, loff_t *ppos)
-{
- struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
- struct mdev_parent *parent = mdev->type->parent;
-
- if (unlikely(!parent->ops->read))
- return -EINVAL;
-
- return parent->ops->read(mdev, buf, count, ppos);
-}
-
-static ssize_t vfio_mdev_write(struct vfio_device *core_vdev,
- const char __user *buf, size_t count,
- loff_t *ppos)
-{
- struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
- struct mdev_parent *parent = mdev->type->parent;
-
- if (unlikely(!parent->ops->write))
- return -EINVAL;
-
- return parent->ops->write(mdev, buf, count, ppos);
-}
-
-static int vfio_mdev_mmap(struct vfio_device *core_vdev,
- struct vm_area_struct *vma)
-{
- struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
- struct mdev_parent *parent = mdev->type->parent;
-
- if (unlikely(!parent->ops->mmap))
- return -EINVAL;
-
- return parent->ops->mmap(mdev, vma);
-}
-
-static void vfio_mdev_request(struct vfio_device *core_vdev, unsigned int count)
-{
- struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
- struct mdev_parent *parent = mdev->type->parent;
-
- if (parent->ops->request)
- parent->ops->request(mdev, count);
- else if (count == 0)
- dev_notice(mdev_dev(mdev),
- "No mdev vendor driver request callback support, blocked until released by user\n");
-}
-
-static const struct vfio_device_ops vfio_mdev_dev_ops = {
- .name = "vfio-mdev",
- .open_device = vfio_mdev_open_device,
- .close_device = vfio_mdev_close_device,
- .ioctl = vfio_mdev_unlocked_ioctl,
- .read = vfio_mdev_read,
- .write = vfio_mdev_write,
- .mmap = vfio_mdev_mmap,
- .request = vfio_mdev_request,
-};
-
-static int vfio_mdev_probe(struct mdev_device *mdev)
-{
- struct vfio_device *vdev;
- int ret;
-
- vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
- if (!vdev)
- return -ENOMEM;
-
- vfio_init_group_dev(vdev, &mdev->dev, &vfio_mdev_dev_ops);
- ret = vfio_register_emulated_iommu_dev(vdev);
- if (ret)
- goto out_uninit;
-
- dev_set_drvdata(&mdev->dev, vdev);
- return 0;
-
-out_uninit:
- vfio_uninit_group_dev(vdev);
- kfree(vdev);
- return ret;
-}
-
-static void vfio_mdev_remove(struct mdev_device *mdev)
-{
- struct vfio_device *vdev = dev_get_drvdata(&mdev->dev);
-
- vfio_unregister_group_dev(vdev);
- vfio_uninit_group_dev(vdev);
- kfree(vdev);
-}
-
-struct mdev_driver vfio_mdev_driver = {
- .driver = {
- .name = "vfio_mdev",
- .owner = THIS_MODULE,
- .mod_name = KBUILD_MODNAME,
- },
- .probe = vfio_mdev_probe,
- .remove = vfio_mdev_remove,
-};
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 15d03f6532d07..192aed656116f 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -40,40 +40,7 @@ struct device *mtype_get_parent_dev(struct mdev_type *mtype);
* @mdev_attr_groups: Attributes of the mediated device.
* @supported_type_groups: Attributes to define supported types. It is mandatory
* to provide supported types.
- * @create: Called to allocate basic resources in parent device's
- * driver for a particular mediated device. It is
- * mandatory to provide create ops.
- * @mdev: mdev_device structure on of mediated device
- * that is being created
- * Returns integer: success (0) or error (< 0)
- * @remove: Called to free resources in parent device's driver for
- * a mediated device. It is mandatory to provide 'remove'
- * ops.
- * @mdev: mdev_device device structure which is being
- * destroyed
- * Returns integer: success (0) or error (< 0)
- * @read: Read emulation callback
- * @mdev: mediated device structure
- * @buf: read buffer
- * @count: number of bytes to read
- * @ppos: address.
- * Retuns number on bytes read on success or error.
- * @write: Write emulation callback
- * @mdev: mediated device structure
- * @buf: write buffer
- * @count: number of bytes to be written
- * @ppos: address.
- * Retuns number on bytes written on success or error.
- * @ioctl: IOCTL callback
- * @mdev: mediated device structure
- * @cmd: ioctl command
- * @arg: arguments to ioctl
- * @mmap: mmap callback
- * @mdev: mediated device structure
- * @vma: vma structure
- * @request: request callback to release device
- * @mdev: mediated device structure
- * @count: request sequence number
+ *
* Parent device that support mediated device should be registered with mdev
* module with mdev_parent_ops structure.
**/
@@ -83,19 +50,6 @@ struct mdev_parent_ops {
const struct attribute_group **dev_attr_groups;
const struct attribute_group **mdev_attr_groups;
struct attribute_group **supported_type_groups;
-
- int (*create)(struct mdev_device *mdev);
- int (*remove)(struct mdev_device *mdev);
- int (*open_device)(struct mdev_device *mdev);
- void (*close_device)(struct mdev_device *mdev);
- ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
- size_t count, loff_t *ppos);
- ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
- size_t count, loff_t *ppos);
- long (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
- unsigned long arg);
- int (*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
- void (*request)(struct mdev_device *mdev, unsigned int count);
};

/* interface for exporting mdev supported type attributes */
--
2.30.2