1 files changed, 427 insertions, 0 deletions
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
new file mode 100644
index 000000000..b558d4cfd
--- /dev/null
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -0,0 +1,427 @@
+// 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;
+
+	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");