ubuntu-linux-kernel/drivers/vfio/mdev/mdev_sysfs.c

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2024-04-01 15:06:58 +00:00
/*
* File attributes for Mediated devices
*
* Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
* Author: Neo Jia <cjia@nvidia.com>
* Kirti Wankhede <kwankhede@nvidia.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/sysfs.h>
#include <linux/ctype.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/uuid.h>
#include <linux/mdev.h>
#include "mdev_private.h"
/* Static functions */
static ssize_t mdev_type_attr_show(struct kobject *kobj,
struct attribute *__attr, char *buf)
{
struct mdev_type_attribute *attr = to_mdev_type_attr(__attr);
struct mdev_type *type = to_mdev_type(kobj);
ssize_t ret = -EIO;
if (attr->show)
ret = attr->show(kobj, type->parent->dev, buf);
return ret;
}
static ssize_t mdev_type_attr_store(struct kobject *kobj,
struct attribute *__attr,
const char *buf, size_t count)
{
struct mdev_type_attribute *attr = to_mdev_type_attr(__attr);
struct mdev_type *type = to_mdev_type(kobj);
ssize_t ret = -EIO;
if (attr->store)
ret = attr->store(&type->kobj, type->parent->dev, buf, count);
return ret;
}
static const struct sysfs_ops mdev_type_sysfs_ops = {
.show = mdev_type_attr_show,
.store = mdev_type_attr_store,
};
static ssize_t create_store(struct kobject *kobj, struct device *dev,
const char *buf, size_t count)
{
char *str;
uuid_le uuid;
int ret;
if ((count < UUID_STRING_LEN) || (count > UUID_STRING_LEN + 1))
return -EINVAL;
str = kstrndup(buf, count, GFP_KERNEL);
if (!str)
return -ENOMEM;
ret = uuid_le_to_bin(str, &uuid);
kfree(str);
if (ret)
return ret;
ret = mdev_device_create(kobj, dev, uuid);
if (ret)
return ret;
return count;
}
MDEV_TYPE_ATTR_WO(create);
static void mdev_type_release(struct kobject *kobj)
{
struct mdev_type *type = to_mdev_type(kobj);
pr_debug("Releasing group %s\n", kobj->name);
kfree(type);
}
static struct kobj_type mdev_type_ktype = {
.sysfs_ops = &mdev_type_sysfs_ops,
.release = mdev_type_release,
};
struct mdev_type *add_mdev_supported_type(struct mdev_parent *parent,
struct attribute_group *group)
{
struct mdev_type *type;
int ret;
if (!group->name) {
pr_err("%s: Type name empty!\n", __func__);
return ERR_PTR(-EINVAL);
}
type = kzalloc(sizeof(*type), GFP_KERNEL);
if (!type)
return ERR_PTR(-ENOMEM);
type->kobj.kset = parent->mdev_types_kset;
ret = kobject_init_and_add(&type->kobj, &mdev_type_ktype, NULL,
"%s-%s", dev_driver_string(parent->dev),
group->name);
if (ret) {
kfree(type);
return ERR_PTR(ret);
}
ret = sysfs_create_file(&type->kobj, &mdev_type_attr_create.attr);
if (ret)
goto attr_create_failed;
type->devices_kobj = kobject_create_and_add("devices", &type->kobj);
if (!type->devices_kobj) {
ret = -ENOMEM;
goto attr_devices_failed;
}
ret = sysfs_create_files(&type->kobj,
(const struct attribute **)group->attrs);
if (ret) {
ret = -ENOMEM;
goto attrs_failed;
}
type->group = group;
type->parent = parent;
return type;
attrs_failed:
kobject_put(type->devices_kobj);
attr_devices_failed:
sysfs_remove_file(&type->kobj, &mdev_type_attr_create.attr);
attr_create_failed:
kobject_del(&type->kobj);
kobject_put(&type->kobj);
return ERR_PTR(ret);
}
static void remove_mdev_supported_type(struct mdev_type *type)
{
sysfs_remove_files(&type->kobj,
(const struct attribute **)type->group->attrs);
kobject_put(type->devices_kobj);
sysfs_remove_file(&type->kobj, &mdev_type_attr_create.attr);
kobject_del(&type->kobj);
kobject_put(&type->kobj);
}
static int add_mdev_supported_type_groups(struct mdev_parent *parent)
{
int i;
for (i = 0; parent->ops->supported_type_groups[i]; i++) {
struct mdev_type *type;
type = add_mdev_supported_type(parent,
parent->ops->supported_type_groups[i]);
if (IS_ERR(type)) {
struct mdev_type *ltype, *tmp;
list_for_each_entry_safe(ltype, tmp, &parent->type_list,
next) {
list_del(&ltype->next);
remove_mdev_supported_type(ltype);
}
return PTR_ERR(type);
}
list_add(&type->next, &parent->type_list);
}
return 0;
}
/* mdev sysfs functions */
void parent_remove_sysfs_files(struct mdev_parent *parent)
{
struct mdev_type *type, *tmp;
list_for_each_entry_safe(type, tmp, &parent->type_list, next) {
list_del(&type->next);
remove_mdev_supported_type(type);
}
sysfs_remove_groups(&parent->dev->kobj, parent->ops->dev_attr_groups);
kset_unregister(parent->mdev_types_kset);
}
int parent_create_sysfs_files(struct mdev_parent *parent)
{
int ret;
parent->mdev_types_kset = kset_create_and_add("mdev_supported_types",
NULL, &parent->dev->kobj);
if (!parent->mdev_types_kset)
return -ENOMEM;
INIT_LIST_HEAD(&parent->type_list);
ret = sysfs_create_groups(&parent->dev->kobj,
parent->ops->dev_attr_groups);
if (ret)
goto create_err;
ret = add_mdev_supported_type_groups(parent);
if (ret)
sysfs_remove_groups(&parent->dev->kobj,
parent->ops->dev_attr_groups);
else
return ret;
create_err:
kset_unregister(parent->mdev_types_kset);
return ret;
}
static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
unsigned long val;
if (kstrtoul(buf, 0, &val) < 0)
return -EINVAL;
if (val && device_remove_file_self(dev, attr)) {
int ret;
ret = mdev_device_remove(dev, false);
if (ret) {
device_create_file(dev, attr);
return ret;
}
}
return count;
}
static DEVICE_ATTR_WO(remove);
static const struct attribute *mdev_device_attrs[] = {
&dev_attr_remove.attr,
NULL,
};
int mdev_create_sysfs_files(struct device *dev, struct mdev_type *type)
{
int ret;
ret = sysfs_create_files(&dev->kobj, mdev_device_attrs);
if (ret)
return ret;
ret = sysfs_create_link(type->devices_kobj, &dev->kobj, dev_name(dev));
if (ret)
goto device_link_failed;
ret = sysfs_create_link(&dev->kobj, &type->kobj, "mdev_type");
if (ret)
goto type_link_failed;
return ret;
type_link_failed:
sysfs_remove_link(type->devices_kobj, dev_name(dev));
device_link_failed:
sysfs_remove_files(&dev->kobj, mdev_device_attrs);
return ret;
}
void mdev_remove_sysfs_files(struct device *dev, struct mdev_type *type)
{
sysfs_remove_link(&dev->kobj, "mdev_type");
sysfs_remove_link(type->devices_kobj, dev_name(dev));
sysfs_remove_files(&dev->kobj, mdev_device_attrs);
}