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 const guid_t *mdev_uuid(struct mdev_device *mdev)
67 EXPORT_SYMBOL(mdev_uuid);
69 /* Should be called holding parent_list_lock */
70 static struct mdev_parent *__find_parent_device(struct device *dev)
72 struct mdev_parent *parent;
74 list_for_each_entry(parent, &parent_list, next) {
75 if (parent->dev == dev)
81 static void mdev_release_parent(struct kref *kref)
83 struct mdev_parent *parent = container_of(kref, struct mdev_parent,
85 struct device *dev = parent->dev;
91 static inline struct mdev_parent *mdev_get_parent(struct mdev_parent *parent)
94 kref_get(&parent->ref);
99 static inline void mdev_put_parent(struct mdev_parent *parent)
102 kref_put(&parent->ref, mdev_release_parent);
105 static int mdev_device_create_ops(struct kobject *kobj,
106 struct mdev_device *mdev)
108 struct mdev_parent *parent = mdev->parent;
111 ret = parent->ops->create(kobj, mdev);
115 ret = sysfs_create_groups(&mdev->dev.kobj,
116 parent->ops->mdev_attr_groups);
118 parent->ops->remove(mdev);
124 * mdev_device_remove_ops gets called from sysfs's 'remove' and when parent
125 * device is being unregistered from mdev device framework.
126 * - 'force_remove' is set to 'false' when called from sysfs's 'remove' which
127 * indicates that if the mdev device is active, used by VMM or userspace
128 * application, vendor driver could return error then don't remove the device.
129 * - 'force_remove' is set to 'true' when called from mdev_unregister_device()
130 * which indicate that parent device is being removed from mdev device
131 * framework so remove mdev device forcefully.
133 static int mdev_device_remove_ops(struct mdev_device *mdev, bool force_remove)
135 struct mdev_parent *parent = mdev->parent;
139 * Vendor driver can return error if VMM or userspace application is
140 * using this mdev device.
142 ret = parent->ops->remove(mdev);
143 if (ret && !force_remove)
146 sysfs_remove_groups(&mdev->dev.kobj, parent->ops->mdev_attr_groups);
150 static int mdev_device_remove_cb(struct device *dev, void *data)
152 if (!dev_is_mdev(dev))
155 return mdev_device_remove(dev, data ? *(bool *)data : true);
159 * mdev_register_device : Register a device
160 * @dev: device structure representing parent device.
161 * @ops: Parent device operation structure to be registered.
163 * Add device to list of registered parent devices.
164 * Returns a negative value on error, otherwise 0.
166 int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
169 struct mdev_parent *parent;
171 /* check for mandatory ops */
172 if (!ops || !ops->create || !ops->remove || !ops->supported_type_groups)
175 dev = get_device(dev);
179 mutex_lock(&parent_list_lock);
181 /* Check for duplicate */
182 parent = __find_parent_device(dev);
188 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
194 kref_init(&parent->ref);
199 if (!mdev_bus_compat_class) {
200 mdev_bus_compat_class = class_compat_register("mdev_bus");
201 if (!mdev_bus_compat_class) {
207 ret = parent_create_sysfs_files(parent);
211 ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL);
213 dev_warn(dev, "Failed to create compatibility class link\n");
215 list_add(&parent->next, &parent_list);
216 mutex_unlock(&parent_list_lock);
218 dev_info(dev, "MDEV: Registered\n");
222 mutex_unlock(&parent_list_lock);
224 mdev_put_parent(parent);
229 EXPORT_SYMBOL(mdev_register_device);
232 * mdev_unregister_device : Unregister a parent device
233 * @dev: device structure representing parent device.
235 * Remove device from list of registered parent devices. Give a chance to free
236 * existing mediated devices for given device.
239 void mdev_unregister_device(struct device *dev)
241 struct mdev_parent *parent;
242 bool force_remove = true;
244 mutex_lock(&parent_list_lock);
245 parent = __find_parent_device(dev);
248 mutex_unlock(&parent_list_lock);
251 dev_info(dev, "MDEV: Unregistering\n");
253 list_del(&parent->next);
254 class_compat_remove_link(mdev_bus_compat_class, dev, NULL);
256 device_for_each_child(dev, (void *)&force_remove,
257 mdev_device_remove_cb);
259 parent_remove_sysfs_files(parent);
261 mutex_unlock(&parent_list_lock);
262 mdev_put_parent(parent);
264 EXPORT_SYMBOL(mdev_unregister_device);
266 static void mdev_device_release(struct device *dev)
268 struct mdev_device *mdev = to_mdev_device(dev);
270 mutex_lock(&mdev_list_lock);
271 list_del(&mdev->next);
272 mutex_unlock(&mdev_list_lock);
274 dev_dbg(&mdev->dev, "MDEV: destroying\n");
278 int mdev_device_create(struct kobject *kobj,
279 struct device *dev, const guid_t *uuid)
282 struct mdev_device *mdev, *tmp;
283 struct mdev_parent *parent;
284 struct mdev_type *type = to_mdev_type(kobj);
286 parent = mdev_get_parent(type->parent);
290 mutex_lock(&mdev_list_lock);
292 /* Check for duplicate */
293 list_for_each_entry(tmp, &mdev_list, next) {
294 if (guid_equal(&tmp->uuid, uuid)) {
295 mutex_unlock(&mdev_list_lock);
301 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
303 mutex_unlock(&mdev_list_lock);
308 guid_copy(&mdev->uuid, uuid);
309 list_add(&mdev->next, &mdev_list);
310 mutex_unlock(&mdev_list_lock);
312 mdev->parent = parent;
313 kref_init(&mdev->ref);
315 mdev->dev.parent = dev;
316 mdev->dev.bus = &mdev_bus_type;
317 mdev->dev.release = mdev_device_release;
318 dev_set_name(&mdev->dev, "%pUl", uuid);
320 ret = device_register(&mdev->dev);
322 put_device(&mdev->dev);
326 ret = mdev_device_create_ops(kobj, mdev);
330 ret = mdev_create_sysfs_files(&mdev->dev, type);
332 mdev_device_remove_ops(mdev, true);
336 mdev->type_kobj = kobj;
338 dev_dbg(&mdev->dev, "MDEV: created\n");
343 device_unregister(&mdev->dev);
345 mdev_put_parent(parent);
349 int mdev_device_remove(struct device *dev, bool force_remove)
351 struct mdev_device *mdev, *tmp;
352 struct mdev_parent *parent;
353 struct mdev_type *type;
356 mdev = to_mdev_device(dev);
358 mutex_lock(&mdev_list_lock);
359 list_for_each_entry(tmp, &mdev_list, next) {
365 mutex_unlock(&mdev_list_lock);
370 mutex_unlock(&mdev_list_lock);
374 mdev->active = false;
375 mutex_unlock(&mdev_list_lock);
377 type = to_mdev_type(mdev->type_kobj);
378 parent = mdev->parent;
380 ret = mdev_device_remove_ops(mdev, force_remove);
386 mdev_remove_sysfs_files(dev, type);
387 device_unregister(dev);
388 mdev_put_parent(parent);
393 static int __init mdev_init(void)
395 return mdev_bus_register();
398 static void __exit mdev_exit(void)
400 if (mdev_bus_compat_class)
401 class_compat_unregister(mdev_bus_compat_class);
403 mdev_bus_unregister();
406 module_init(mdev_init)
407 module_exit(mdev_exit)
409 MODULE_VERSION(DRIVER_VERSION);
410 MODULE_LICENSE("GPL v2");
411 MODULE_AUTHOR(DRIVER_AUTHOR);
412 MODULE_DESCRIPTION(DRIVER_DESC);
413 MODULE_SOFTDEP("post: vfio_mdev");