2 * Mediated device Core Driver
4 * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
5 * Author: Neo Jia <cjia@nvidia.com>
6 * Kirti Wankhede <kwankhede@nvidia.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/module.h>
14 #include <linux/device.h>
15 #include <linux/slab.h>
16 #include <linux/uuid.h>
17 #include <linux/sysfs.h>
18 #include <linux/mdev.h>
20 #include "mdev_private.h"
22 #define DRIVER_VERSION "0.1"
23 #define DRIVER_AUTHOR "NVIDIA Corporation"
24 #define DRIVER_DESC "Mediated device Core Driver"
26 static LIST_HEAD(parent_list);
27 static DEFINE_MUTEX(parent_list_lock);
28 static struct class_compat *mdev_bus_compat_class;
30 static LIST_HEAD(mdev_list);
31 static DEFINE_MUTEX(mdev_list_lock);
33 struct device *mdev_parent_dev(struct mdev_device *mdev)
35 return mdev->parent->dev;
37 EXPORT_SYMBOL(mdev_parent_dev);
39 void *mdev_get_drvdata(struct mdev_device *mdev)
41 return mdev->driver_data;
43 EXPORT_SYMBOL(mdev_get_drvdata);
45 void mdev_set_drvdata(struct mdev_device *mdev, void *data)
47 mdev->driver_data = data;
49 EXPORT_SYMBOL(mdev_set_drvdata);
51 struct device *mdev_dev(struct mdev_device *mdev)
55 EXPORT_SYMBOL(mdev_dev);
57 struct mdev_device *mdev_from_dev(struct device *dev)
59 return dev_is_mdev(dev) ? to_mdev_device(dev) : NULL;
61 EXPORT_SYMBOL(mdev_from_dev);
63 uuid_le mdev_uuid(struct mdev_device *mdev)
67 EXPORT_SYMBOL(mdev_uuid);
69 static int _find_mdev_device(struct device *dev, void *data)
71 struct mdev_device *mdev;
73 if (!dev_is_mdev(dev))
76 mdev = to_mdev_device(dev);
78 if (uuid_le_cmp(mdev->uuid, *(uuid_le *)data) == 0)
84 static bool mdev_device_exist(struct mdev_parent *parent, uuid_le uuid)
88 dev = device_find_child(parent->dev, &uuid, _find_mdev_device);
97 /* Should be called holding parent_list_lock */
98 static struct mdev_parent *__find_parent_device(struct device *dev)
100 struct mdev_parent *parent;
102 list_for_each_entry(parent, &parent_list, next) {
103 if (parent->dev == dev)
109 static void mdev_release_parent(struct kref *kref)
111 struct mdev_parent *parent = container_of(kref, struct mdev_parent,
113 struct device *dev = parent->dev;
120 inline struct mdev_parent *mdev_get_parent(struct mdev_parent *parent)
123 kref_get(&parent->ref);
128 static inline void mdev_put_parent(struct mdev_parent *parent)
131 kref_put(&parent->ref, mdev_release_parent);
134 static int mdev_device_create_ops(struct kobject *kobj,
135 struct mdev_device *mdev)
137 struct mdev_parent *parent = mdev->parent;
140 ret = parent->ops->create(kobj, mdev);
144 ret = sysfs_create_groups(&mdev->dev.kobj,
145 parent->ops->mdev_attr_groups);
147 parent->ops->remove(mdev);
153 * mdev_device_remove_ops gets called from sysfs's 'remove' and when parent
154 * device is being unregistered from mdev device framework.
155 * - 'force_remove' is set to 'false' when called from sysfs's 'remove' which
156 * indicates that if the mdev device is active, used by VMM or userspace
157 * application, vendor driver could return error then don't remove the device.
158 * - 'force_remove' is set to 'true' when called from mdev_unregister_device()
159 * which indicate that parent device is being removed from mdev device
160 * framework so remove mdev device forcefully.
162 static int mdev_device_remove_ops(struct mdev_device *mdev, bool force_remove)
164 struct mdev_parent *parent = mdev->parent;
168 * Vendor driver can return error if VMM or userspace application is
169 * using this mdev device.
171 ret = parent->ops->remove(mdev);
172 if (ret && !force_remove)
175 sysfs_remove_groups(&mdev->dev.kobj, parent->ops->mdev_attr_groups);
179 static int mdev_device_remove_cb(struct device *dev, void *data)
181 if (!dev_is_mdev(dev))
184 return mdev_device_remove(dev, data ? *(bool *)data : true);
188 * mdev_register_device : Register a device
189 * @dev: device structure representing parent device.
190 * @ops: Parent device operation structure to be registered.
192 * Add device to list of registered parent devices.
193 * Returns a negative value on error, otherwise 0.
195 int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
198 struct mdev_parent *parent;
200 /* check for mandatory ops */
201 if (!ops || !ops->create || !ops->remove || !ops->supported_type_groups)
204 dev = get_device(dev);
208 mutex_lock(&parent_list_lock);
210 /* Check for duplicate */
211 parent = __find_parent_device(dev);
217 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
223 kref_init(&parent->ref);
224 mutex_init(&parent->lock);
229 if (!mdev_bus_compat_class) {
230 mdev_bus_compat_class = class_compat_register("mdev_bus");
231 if (!mdev_bus_compat_class) {
237 ret = parent_create_sysfs_files(parent);
241 ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL);
243 dev_warn(dev, "Failed to create compatibility class link\n");
245 list_add(&parent->next, &parent_list);
246 mutex_unlock(&parent_list_lock);
248 dev_info(dev, "MDEV: Registered\n");
252 mutex_unlock(&parent_list_lock);
254 mdev_put_parent(parent);
259 EXPORT_SYMBOL(mdev_register_device);
262 * mdev_unregister_device : Unregister a parent device
263 * @dev: device structure representing parent device.
265 * Remove device from list of registered parent devices. Give a chance to free
266 * existing mediated devices for given device.
269 void mdev_unregister_device(struct device *dev)
271 struct mdev_parent *parent;
272 bool force_remove = true;
274 mutex_lock(&parent_list_lock);
275 parent = __find_parent_device(dev);
278 mutex_unlock(&parent_list_lock);
281 dev_info(dev, "MDEV: Unregistering\n");
283 list_del(&parent->next);
284 class_compat_remove_link(mdev_bus_compat_class, dev, NULL);
286 device_for_each_child(dev, (void *)&force_remove,
287 mdev_device_remove_cb);
289 parent_remove_sysfs_files(parent);
291 mutex_unlock(&parent_list_lock);
292 mdev_put_parent(parent);
294 EXPORT_SYMBOL(mdev_unregister_device);
296 static void mdev_device_release(struct device *dev)
298 struct mdev_device *mdev = to_mdev_device(dev);
300 dev_dbg(&mdev->dev, "MDEV: destroying\n");
304 int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid)
307 struct mdev_device *mdev;
308 struct mdev_parent *parent;
309 struct mdev_type *type = to_mdev_type(kobj);
311 parent = mdev_get_parent(type->parent);
315 mutex_lock(&parent->lock);
317 /* Check for duplicate */
318 if (mdev_device_exist(parent, uuid)) {
323 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
329 memcpy(&mdev->uuid, &uuid, sizeof(uuid_le));
330 mdev->parent = parent;
331 kref_init(&mdev->ref);
333 mdev->dev.parent = dev;
334 mdev->dev.bus = &mdev_bus_type;
335 mdev->dev.release = mdev_device_release;
336 dev_set_name(&mdev->dev, "%pUl", uuid.b);
338 ret = device_register(&mdev->dev);
340 put_device(&mdev->dev);
344 ret = mdev_device_create_ops(kobj, mdev);
348 ret = mdev_create_sysfs_files(&mdev->dev, type);
350 mdev_device_remove_ops(mdev, true);
354 mdev->type_kobj = kobj;
355 dev_dbg(&mdev->dev, "MDEV: created\n");
357 mutex_unlock(&parent->lock);
359 mutex_lock(&mdev_list_lock);
360 list_add(&mdev->next, &mdev_list);
361 mutex_unlock(&mdev_list_lock);
366 device_unregister(&mdev->dev);
369 mutex_unlock(&parent->lock);
370 mdev_put_parent(parent);
374 int mdev_device_remove(struct device *dev, bool force_remove)
376 struct mdev_device *mdev, *tmp;
377 struct mdev_parent *parent;
378 struct mdev_type *type;
382 mdev = to_mdev_device(dev);
384 mutex_lock(&mdev_list_lock);
385 list_for_each_entry(tmp, &mdev_list, next) {
393 list_del(&mdev->next);
395 mutex_unlock(&mdev_list_lock);
400 type = to_mdev_type(mdev->type_kobj);
401 parent = mdev->parent;
402 mutex_lock(&parent->lock);
404 ret = mdev_device_remove_ops(mdev, force_remove);
406 mutex_unlock(&parent->lock);
408 mutex_lock(&mdev_list_lock);
409 list_add(&mdev->next, &mdev_list);
410 mutex_unlock(&mdev_list_lock);
415 mdev_remove_sysfs_files(dev, type);
416 device_unregister(dev);
417 mutex_unlock(&parent->lock);
418 mdev_put_parent(parent);
423 static int __init mdev_init(void)
427 ret = mdev_bus_register();
430 * Attempt to load known vfio_mdev. This gives us a working environment
431 * without the user needing to explicitly load vfio_mdev driver.
434 request_module_nowait("vfio_mdev");
439 static void __exit mdev_exit(void)
441 if (mdev_bus_compat_class)
442 class_compat_unregister(mdev_bus_compat_class);
444 mdev_bus_unregister();
447 module_init(mdev_init)
448 module_exit(mdev_exit)
450 MODULE_VERSION(DRIVER_VERSION);
451 MODULE_LICENSE("GPL v2");
452 MODULE_AUTHOR(DRIVER_AUTHOR);
453 MODULE_DESCRIPTION(DRIVER_DESC);