Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 275 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..ed4737de4
--- /dev/null
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -0,0 +1,275 @@
+// 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/slab.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 struct class_compat *mdev_bus_compat_class;
+
+static LIST_HEAD(mdev_list);
+static DEFINE_MUTEX(mdev_list_lock);
+
+/* 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;
+
+	mdev_remove_sysfs_files(mdev);
+	device_del(&mdev->dev);
+	lockdep_assert_held(&parent->unreg_sem);
+	/* Balances with device_initialize() */
+	put_device(&mdev->dev);
+}
+
+static int mdev_device_remove_cb(struct device *dev, void *data)
+{
+	if (dev->bus == &mdev_bus_type)
+		mdev_device_remove_common(to_mdev_device(dev));
+	return 0;
+}
+
+/*
+ * mdev_register_parent: Register a device as parent for mdevs
+ * @parent: parent structure registered
+ * @dev: device structure representing parent device.
+ * @mdev_driver: Device driver to bind to the newly created mdev
+ * @types: Array of supported mdev types
+ * @nr_types: Number of entries in @types
+ *
+ * Registers the @parent stucture as a parent for mdev types and thus mdev
+ * devices.  The caller needs to hold a reference on @dev that must not be
+ * released until after the call to mdev_unregister_parent().
+ *
+ * Returns a negative value on error, otherwise 0.
+ */
+int mdev_register_parent(struct mdev_parent *parent, struct device *dev,
+		struct mdev_driver *mdev_driver, struct mdev_type **types,
+		unsigned int nr_types)
+{
+	char *env_string = "MDEV_STATE=registered";
+	char *envp[] = { env_string, NULL };
+	int ret;
+
+	memset(parent, 0, sizeof(*parent));
+	init_rwsem(&parent->unreg_sem);
+	parent->dev = dev;
+	parent->mdev_driver = mdev_driver;
+	parent->types = types;
+	parent->nr_types = nr_types;
+	atomic_set(&parent->available_instances, mdev_driver->max_instances);
+
+	ret = parent_create_sysfs_files(parent);
+	if (ret)
+		return ret;
+
+	ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL);
+	if (ret)
+		dev_warn(dev, "Failed to create compatibility class link\n");
+
+	dev_info(dev, "MDEV: Registered\n");
+	kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
+	return 0;
+}
+EXPORT_SYMBOL(mdev_register_parent);
+
+/*
+ * mdev_unregister_parent : Unregister a parent device
+ * @parent: parent structure to unregister
+ */
+void mdev_unregister_parent(struct mdev_parent *parent)
+{
+	char *env_string = "MDEV_STATE=unregistered";
+	char *envp[] = { env_string, NULL };
+
+	dev_info(parent->dev, "MDEV: Unregistering\n");
+
+	down_write(&parent->unreg_sem);
+	class_compat_remove_link(mdev_bus_compat_class, parent->dev, NULL);
+	device_for_each_child(parent->dev, NULL, mdev_device_remove_cb);
+	parent_remove_sysfs_files(parent);
+	up_write(&parent->unreg_sem);
+
+	kobject_uevent_env(&parent->dev->kobj, KOBJ_CHANGE, envp);
+}
+EXPORT_SYMBOL(mdev_unregister_parent);
+
+static void mdev_device_release(struct device *dev)
+{
+	struct mdev_device *mdev = to_mdev_device(dev);
+	struct mdev_parent *parent = mdev->type->parent;
+
+	mutex_lock(&mdev_list_lock);
+	list_del(&mdev->next);
+	if (!parent->mdev_driver->get_available)
+		atomic_inc(&parent->available_instances);
+	mutex_unlock(&mdev_list_lock);
+
+	/* Pairs with the get in mdev_device_create() */
+	kobject_put(&mdev->type->kobj);
+
+	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->mdev_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;
+		}
+	}
+
+	if (!drv->get_available) {
+		/*
+		 * Note: that non-atomic read and dec is fine here because
+		 * all modifications are under mdev_list_lock.
+		 */
+		if (!atomic_read(&parent->available_instances)) {
+			mutex_unlock(&mdev_list_lock);
+			return -EUSERS;
+		}
+		atomic_dec(&parent->available_instances);
+	}
+
+	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 = mdev_device_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;
+	}
+
+	ret = device_add(&mdev->dev);
+	if (ret)
+		goto out_unlock;
+
+	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_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 ret;
+
+	ret = bus_register(&mdev_bus_type);
+	if (ret)
+		return ret;
+
+	mdev_bus_compat_class = class_compat_register("mdev_bus");
+	if (!mdev_bus_compat_class) {
+		bus_unregister(&mdev_bus_type);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void __exit mdev_exit(void)
+{
+	class_compat_unregister(mdev_bus_compat_class);
+	bus_unregister(&mdev_bus_type);
+}
+
+subsys_initcall(mdev_init)
+module_exit(mdev_exit)
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);