blob: 6de97d25a3f87da67c297ea81b8a88f547c7e4e5 [file] [log] [blame]
// 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->parent->dev;
}
EXPORT_SYMBOL(mdev_parent_dev);
void *mdev_get_drvdata(struct mdev_device *mdev)
{
return mdev->driver_data;
}
EXPORT_SYMBOL(mdev_get_drvdata);
void mdev_set_drvdata(struct mdev_device *mdev, void *data)
{
mdev->driver_data = data;
}
EXPORT_SYMBOL(mdev_set_drvdata);
struct device *mdev_dev(struct mdev_device *mdev)
{
return &mdev->dev;
}
EXPORT_SYMBOL(mdev_dev);
struct mdev_device *mdev_from_dev(struct device *dev)
{
return dev_is_mdev(dev) ? to_mdev_device(dev) : NULL;
}
EXPORT_SYMBOL(mdev_from_dev);
const guid_t *mdev_uuid(struct mdev_device *mdev)
{
return &mdev->uuid;
}
EXPORT_SYMBOL(mdev_uuid);
/* 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;
}
static 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);
}
static struct mdev_parent *mdev_get_parent(struct mdev_parent *parent)
{
if (parent)
kref_get(&parent->ref);
return parent;
}
static void mdev_put_parent(struct mdev_parent *parent)
{
if (parent)
kref_put(&parent->ref, mdev_release_parent);
}
/* Caller must hold parent unreg_sem read or write lock */
static void mdev_device_remove_common(struct mdev_device *mdev)
{
struct mdev_parent *parent;
struct mdev_type *type;
int ret;
type = to_mdev_type(mdev->type_kobj);
mdev_remove_sysfs_files(&mdev->dev, type);
device_del(&mdev->dev);
parent = mdev->parent;
lockdep_assert_held(&parent->unreg_sem);
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);
mdev_put_parent(parent);
}
static int mdev_device_remove_cb(struct device *dev, void *data)
{
if (dev_is_mdev(dev)) {
struct mdev_device *mdev;
mdev = to_mdev_device(dev);
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->create || !ops->remove || !ops->supported_type_groups)
return -EINVAL;
dev = get_device(dev);
if (!dev)
return -EINVAL;
/* Not mandatory, but its absence could be a problem */
if (!ops->request)
dev_info(dev, "Driver cannot be asked to release device\n");
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_free(struct mdev_device *mdev)
{
mutex_lock(&mdev_list_lock);
list_del(&mdev->next);
mutex_unlock(&mdev_list_lock);
dev_dbg(&mdev->dev, "MDEV: destroying\n");
kfree(mdev);
}
static void mdev_device_release(struct device *dev)
{
struct mdev_device *mdev = to_mdev_device(dev);
mdev_device_free(mdev);
}
int mdev_device_create(struct kobject *kobj,
struct device *dev, const guid_t *uuid)
{
int ret;
struct mdev_device *mdev, *tmp;
struct mdev_parent *parent;
struct mdev_type *type = to_mdev_type(kobj);
parent = mdev_get_parent(type->parent);
if (!parent)
return -EINVAL;
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);
ret = -EEXIST;
goto mdev_fail;
}
}
mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
if (!mdev) {
mutex_unlock(&mdev_list_lock);
ret = -ENOMEM;
goto mdev_fail;
}
guid_copy(&mdev->uuid, uuid);
list_add(&mdev->next, &mdev_list);
mutex_unlock(&mdev_list_lock);
mdev->parent = parent;
/* Check if parent unregistration has started */
if (!down_read_trylock(&parent->unreg_sem)) {
mdev_device_free(mdev);
ret = -ENODEV;
goto mdev_fail;
}
device_initialize(&mdev->dev);
mdev->dev.parent = dev;
mdev->dev.bus = &mdev_bus_type;
mdev->dev.release = mdev_device_release;
dev_set_name(&mdev->dev, "%pUl", uuid);
mdev->dev.groups = parent->ops->mdev_attr_groups;
mdev->type_kobj = kobj;
ret = parent->ops->create(kobj, mdev);
if (ret)
goto ops_create_fail;
ret = device_add(&mdev->dev);
if (ret)
goto add_fail;
ret = mdev_create_sysfs_files(&mdev->dev, type);
if (ret)
goto sysfs_fail;
mdev->active = true;
dev_dbg(&mdev->dev, "MDEV: created\n");
up_read(&parent->unreg_sem);
return 0;
sysfs_fail:
device_del(&mdev->dev);
add_fail:
parent->ops->remove(mdev);
ops_create_fail:
up_read(&parent->unreg_sem);
put_device(&mdev->dev);
mdev_fail:
mdev_put_parent(parent);
return ret;
}
int mdev_device_remove(struct device *dev)
{
struct mdev_device *mdev, *tmp;
struct mdev_parent *parent;
mdev = to_mdev_device(dev);
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);
parent = mdev->parent;
/* 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;
}
int mdev_set_iommu_device(struct device *dev, struct device *iommu_device)
{
struct mdev_device *mdev = to_mdev_device(dev);
mdev->iommu_device = iommu_device;
return 0;
}
EXPORT_SYMBOL(mdev_set_iommu_device);
struct device *mdev_get_iommu_device(struct device *dev)
{
struct mdev_device *mdev = to_mdev_device(dev);
return mdev->iommu_device;
}
EXPORT_SYMBOL(mdev_get_iommu_device);
static int __init mdev_init(void)
{
return mdev_bus_register();
}
static void __exit mdev_exit(void)
{
if (mdev_bus_compat_class)
class_compat_unregister(mdev_bus_compat_class);
mdev_bus_unregister();
}
module_init(mdev_init)
module_exit(mdev_exit)
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_SOFTDEP("post: vfio_mdev");