linux-stable/drivers/vfio/mdev/mdev_core.c
Christoph Hellwig 3fb1712d85 vfio/mdev: don't warn if ->request is not set
Only a single driver actually sets the ->request method, so don't print
a scary warning if it isn't.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20210726143524.155779-3-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-08-02 15:23:43 -06:00

403 lines
8.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Mediated device Core Driver
*
* Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
* Author: Neo Jia <cjia@nvidia.com>
* Kirti Wankhede <kwankhede@nvidia.com>
*/
#include <linux/module.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/uuid.h>
#include <linux/sysfs.h>
#include <linux/mdev.h>
#include "mdev_private.h"
#define DRIVER_VERSION "0.1"
#define DRIVER_AUTHOR "NVIDIA Corporation"
#define DRIVER_DESC "Mediated device Core Driver"
static LIST_HEAD(parent_list);
static DEFINE_MUTEX(parent_list_lock);
static struct class_compat *mdev_bus_compat_class;
static LIST_HEAD(mdev_list);
static DEFINE_MUTEX(mdev_list_lock);
struct device *mdev_parent_dev(struct mdev_device *mdev)
{
return mdev->type->parent->dev;
}
EXPORT_SYMBOL(mdev_parent_dev);
/*
* Return the index in supported_type_groups that this mdev_device was created
* from.
*/
unsigned int mdev_get_type_group_id(struct mdev_device *mdev)
{
return mdev->type->type_group_id;
}
EXPORT_SYMBOL(mdev_get_type_group_id);
/*
* Used in mdev_type_attribute sysfs functions to return the index in the
* supported_type_groups that the sysfs is called from.
*/
unsigned int mtype_get_type_group_id(struct mdev_type *mtype)
{
return mtype->type_group_id;
}
EXPORT_SYMBOL(mtype_get_type_group_id);
/*
* Used in mdev_type_attribute sysfs functions to return the parent struct
* device
*/
struct device *mtype_get_parent_dev(struct mdev_type *mtype)
{
return mtype->parent->dev;
}
EXPORT_SYMBOL(mtype_get_parent_dev);
/* Should be called holding parent_list_lock */
static struct mdev_parent *__find_parent_device(struct device *dev)
{
struct mdev_parent *parent;
list_for_each_entry(parent, &parent_list, next) {
if (parent->dev == dev)
return parent;
}
return NULL;
}
void mdev_release_parent(struct kref *kref)
{
struct mdev_parent *parent = container_of(kref, struct mdev_parent,
ref);
struct device *dev = parent->dev;
kfree(parent);
put_device(dev);
}
/* Caller must hold parent unreg_sem read or write lock */
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);
}
static int mdev_device_remove_cb(struct device *dev, void *data)
{
struct mdev_device *mdev = mdev_from_dev(dev);
if (mdev)
mdev_device_remove_common(mdev);
return 0;
}
/*
* mdev_register_device : Register a device
* @dev: device structure representing parent device.
* @ops: Parent device operation structure to be registered.
*
* Add device to list of registered parent devices.
* Returns a negative value on error, otherwise 0.
*/
int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
{
int ret;
struct mdev_parent *parent;
char *env_string = "MDEV_STATE=registered";
char *envp[] = { env_string, NULL };
/* check for mandatory ops */
if (!ops || !ops->supported_type_groups)
return -EINVAL;
if (!ops->device_driver && (!ops->create || !ops->remove))
return -EINVAL;
dev = get_device(dev);
if (!dev)
return -EINVAL;
mutex_lock(&parent_list_lock);
/* Check for duplicate */
parent = __find_parent_device(dev);
if (parent) {
parent = NULL;
ret = -EEXIST;
goto add_dev_err;
}
parent = kzalloc(sizeof(*parent), GFP_KERNEL);
if (!parent) {
ret = -ENOMEM;
goto add_dev_err;
}
kref_init(&parent->ref);
init_rwsem(&parent->unreg_sem);
parent->dev = dev;
parent->ops = ops;
if (!mdev_bus_compat_class) {
mdev_bus_compat_class = class_compat_register("mdev_bus");
if (!mdev_bus_compat_class) {
ret = -ENOMEM;
goto add_dev_err;
}
}
ret = parent_create_sysfs_files(parent);
if (ret)
goto add_dev_err;
ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL);
if (ret)
dev_warn(dev, "Failed to create compatibility class link\n");
list_add(&parent->next, &parent_list);
mutex_unlock(&parent_list_lock);
dev_info(dev, "MDEV: Registered\n");
kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
return 0;
add_dev_err:
mutex_unlock(&parent_list_lock);
if (parent)
mdev_put_parent(parent);
else
put_device(dev);
return ret;
}
EXPORT_SYMBOL(mdev_register_device);
/*
* mdev_unregister_device : Unregister a parent device
* @dev: device structure representing parent device.
*
* Remove device from list of registered parent devices. Give a chance to free
* existing mediated devices for given device.
*/
void mdev_unregister_device(struct device *dev)
{
struct mdev_parent *parent;
char *env_string = "MDEV_STATE=unregistered";
char *envp[] = { env_string, NULL };
mutex_lock(&parent_list_lock);
parent = __find_parent_device(dev);
if (!parent) {
mutex_unlock(&parent_list_lock);
return;
}
dev_info(dev, "MDEV: Unregistering\n");
list_del(&parent->next);
mutex_unlock(&parent_list_lock);
down_write(&parent->unreg_sem);
class_compat_remove_link(mdev_bus_compat_class, dev, NULL);
device_for_each_child(dev, NULL, mdev_device_remove_cb);
parent_remove_sysfs_files(parent);
up_write(&parent->unreg_sem);
mdev_put_parent(parent);
/* We still have the caller's reference to use for the uevent */
kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
}
EXPORT_SYMBOL(mdev_unregister_device);
static void mdev_device_release(struct device *dev)
{
struct mdev_device *mdev = to_mdev_device(dev);
/* Pairs with the get in mdev_device_create() */
kobject_put(&mdev->type->kobj);
mutex_lock(&mdev_list_lock);
list_del(&mdev->next);
mutex_unlock(&mdev_list_lock);
dev_dbg(&mdev->dev, "MDEV: destroying\n");
kfree(mdev);
}
int mdev_device_create(struct mdev_type *type, const guid_t *uuid)
{
int ret;
struct mdev_device *mdev, *tmp;
struct mdev_parent *parent = type->parent;
struct mdev_driver *drv = parent->ops->device_driver;
mutex_lock(&mdev_list_lock);
/* Check for duplicate */
list_for_each_entry(tmp, &mdev_list, next) {
if (guid_equal(&tmp->uuid, uuid)) {
mutex_unlock(&mdev_list_lock);
return -EEXIST;
}
}
mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
if (!mdev) {
mutex_unlock(&mdev_list_lock);
return -ENOMEM;
}
device_initialize(&mdev->dev);
mdev->dev.parent = parent->dev;
mdev->dev.bus = &mdev_bus_type;
mdev->dev.release = mdev_device_release;
mdev->dev.groups = parent->ops->mdev_attr_groups;
mdev->type = type;
/* Pairs with the put in mdev_device_release() */
kobject_get(&type->kobj);
guid_copy(&mdev->uuid, uuid);
list_add(&mdev->next, &mdev_list);
mutex_unlock(&mdev_list_lock);
ret = dev_set_name(&mdev->dev, "%pUl", uuid);
if (ret)
goto out_put_device;
/* Check if parent unregistration has started */
if (!down_read_trylock(&parent->unreg_sem)) {
ret = -ENODEV;
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;
if (!drv)
drv = &vfio_mdev_driver;
ret = device_driver_attach(&drv->driver, &mdev->dev);
if (ret)
goto out_del;
ret = mdev_create_sysfs_files(mdev);
if (ret)
goto out_del;
mdev->active = true;
dev_dbg(&mdev->dev, "MDEV: created\n");
up_read(&parent->unreg_sem);
return 0;
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:
put_device(&mdev->dev);
return ret;
}
int mdev_device_remove(struct mdev_device *mdev)
{
struct mdev_device *tmp;
struct mdev_parent *parent = mdev->type->parent;
mutex_lock(&mdev_list_lock);
list_for_each_entry(tmp, &mdev_list, next) {
if (tmp == mdev)
break;
}
if (tmp != mdev) {
mutex_unlock(&mdev_list_lock);
return -ENODEV;
}
if (!mdev->active) {
mutex_unlock(&mdev_list_lock);
return -EAGAIN;
}
mdev->active = false;
mutex_unlock(&mdev_list_lock);
/* Check if parent unregistration has started */
if (!down_read_trylock(&parent->unreg_sem))
return -ENODEV;
mdev_device_remove_common(mdev);
up_read(&parent->unreg_sem);
return 0;
}
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;
}
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();
}
subsys_initcall(mdev_init)
module_exit(mdev_exit)
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);