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path: root/drivers/vfio/mdev/mdev_core.c
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Diffstat (limited to 'drivers/vfio/mdev/mdev_core.c')
-rw-r--r--drivers/vfio/mdev/mdev_core.c374
1 files changed, 374 insertions, 0 deletions
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
new file mode 100644
index 000000000000..613e8a8a3b2a
--- /dev/null
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -0,0 +1,374 @@
+/*
+ * Mediated device Core Driver
+ *
+ * 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/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 int _find_mdev_device(struct device *dev, void *data)
+{
+ struct mdev_device *mdev;
+
+ if (!dev_is_mdev(dev))
+ return 0;
+
+ mdev = to_mdev_device(dev);
+
+ if (uuid_le_cmp(mdev->uuid, *(uuid_le *)data) == 0)
+ return 1;
+
+ return 0;
+}
+
+static bool mdev_device_exist(struct parent_device *parent, uuid_le uuid)
+{
+ struct device *dev;
+
+ dev = device_find_child(parent->dev, &uuid, _find_mdev_device);
+ if (dev) {
+ put_device(dev);
+ return true;
+ }
+
+ return false;
+}
+
+/* Should be called holding parent_list_lock */
+static struct parent_device *__find_parent_device(struct device *dev)
+{
+ struct parent_device *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 parent_device *parent = container_of(kref, struct parent_device,
+ ref);
+ struct device *dev = parent->dev;
+
+ kfree(parent);
+ put_device(dev);
+}
+
+static
+inline struct parent_device *mdev_get_parent(struct parent_device *parent)
+{
+ if (parent)
+ kref_get(&parent->ref);
+
+ return parent;
+}
+
+static inline void mdev_put_parent(struct parent_device *parent)
+{
+ if (parent)
+ kref_put(&parent->ref, mdev_release_parent);
+}
+
+static int mdev_device_create_ops(struct kobject *kobj,
+ struct mdev_device *mdev)
+{
+ struct parent_device *parent = mdev->parent;
+ int ret;
+
+ ret = parent->ops->create(kobj, mdev);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_groups(&mdev->dev.kobj,
+ parent->ops->mdev_attr_groups);
+ if (ret)
+ parent->ops->remove(mdev);
+
+ return ret;
+}
+
+/*
+ * mdev_device_remove_ops gets called from sysfs's 'remove' and when parent
+ * device is being unregistered from mdev device framework.
+ * - 'force_remove' is set to 'false' when called from sysfs's 'remove' which
+ * indicates that if the mdev device is active, used by VMM or userspace
+ * application, vendor driver could return error then don't remove the device.
+ * - 'force_remove' is set to 'true' when called from mdev_unregister_device()
+ * which indicate that parent device is being removed from mdev device
+ * framework so remove mdev device forcefully.
+ */
+static int mdev_device_remove_ops(struct mdev_device *mdev, bool force_remove)
+{
+ struct parent_device *parent = mdev->parent;
+ int ret;
+
+ /*
+ * Vendor driver can return error if VMM or userspace application is
+ * using this mdev device.
+ */
+ ret = parent->ops->remove(mdev);
+ if (ret && !force_remove)
+ return -EBUSY;
+
+ sysfs_remove_groups(&mdev->dev.kobj, parent->ops->mdev_attr_groups);
+ return 0;
+}
+
+static int mdev_device_remove_cb(struct device *dev, void *data)
+{
+ if (!dev_is_mdev(dev))
+ return 0;
+
+ return mdev_device_remove(dev, data ? *(bool *)data : true);
+}
+
+/*
+ * 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 parent_ops *ops)
+{
+ int ret;
+ struct parent_device *parent;
+
+ /* 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) {
+ ret = -EEXIST;
+ goto add_dev_err;
+ }
+
+ parent = kzalloc(sizeof(*parent), GFP_KERNEL);
+ if (!parent) {
+ ret = -ENOMEM;
+ goto add_dev_err;
+ }
+
+ kref_init(&parent->ref);
+ mutex_init(&parent->lock);
+
+ 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");
+ 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 parent_device *parent;
+ bool force_remove = true;
+
+ 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);
+ class_compat_remove_link(mdev_bus_compat_class, dev, NULL);
+
+ device_for_each_child(dev, (void *)&force_remove,
+ mdev_device_remove_cb);
+
+ parent_remove_sysfs_files(parent);
+
+ mutex_unlock(&parent_list_lock);
+ mdev_put_parent(parent);
+}
+EXPORT_SYMBOL(mdev_unregister_device);
+
+static void mdev_device_release(struct device *dev)
+{
+ struct mdev_device *mdev = to_mdev_device(dev);
+
+ dev_dbg(&mdev->dev, "MDEV: destroying\n");
+ kfree(mdev);
+}
+
+int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid)
+{
+ int ret;
+ struct mdev_device *mdev;
+ struct parent_device *parent;
+ struct mdev_type *type = to_mdev_type(kobj);
+
+ parent = mdev_get_parent(type->parent);
+ if (!parent)
+ return -EINVAL;
+
+ mutex_lock(&parent->lock);
+
+ /* Check for duplicate */
+ if (mdev_device_exist(parent, uuid)) {
+ ret = -EEXIST;
+ goto create_err;
+ }
+
+ mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+ if (!mdev) {
+ ret = -ENOMEM;
+ goto create_err;
+ }
+
+ memcpy(&mdev->uuid, &uuid, sizeof(uuid_le));
+ mdev->parent = parent;
+ kref_init(&mdev->ref);
+
+ mdev->dev.parent = dev;
+ mdev->dev.bus = &mdev_bus_type;
+ mdev->dev.release = mdev_device_release;
+ dev_set_name(&mdev->dev, "%pUl", uuid.b);
+
+ ret = device_register(&mdev->dev);
+ if (ret) {
+ put_device(&mdev->dev);
+ goto create_err;
+ }
+
+ ret = mdev_device_create_ops(kobj, mdev);
+ if (ret)
+ goto create_failed;
+
+ ret = mdev_create_sysfs_files(&mdev->dev, type);
+ if (ret) {
+ mdev_device_remove_ops(mdev, true);
+ goto create_failed;
+ }
+
+ mdev->type_kobj = kobj;
+ dev_dbg(&mdev->dev, "MDEV: created\n");
+
+ mutex_unlock(&parent->lock);
+ return ret;
+
+create_failed:
+ device_unregister(&mdev->dev);
+
+create_err:
+ mutex_unlock(&parent->lock);
+ mdev_put_parent(parent);
+ return ret;
+}
+
+int mdev_device_remove(struct device *dev, bool force_remove)
+{
+ struct mdev_device *mdev;
+ struct parent_device *parent;
+ struct mdev_type *type;
+ int ret;
+
+ mdev = to_mdev_device(dev);
+ type = to_mdev_type(mdev->type_kobj);
+ parent = mdev->parent;
+ mutex_lock(&parent->lock);
+
+ ret = mdev_device_remove_ops(mdev, force_remove);
+ if (ret) {
+ mutex_unlock(&parent->lock);
+ return ret;
+ }
+
+ mdev_remove_sysfs_files(dev, type);
+ device_unregister(dev);
+ mutex_unlock(&parent->lock);
+ mdev_put_parent(parent);
+ return ret;
+}
+
+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);

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