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381 lines
8.4 KiB
381 lines
8.4 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Mediated device Core Driver |
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* |
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* Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. |
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* Author: Neo Jia <[email protected]> |
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* Kirti Wankhede <[email protected]> |
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*/ |
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#include <linux/module.h> |
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#include <linux/device.h> |
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#include <linux/slab.h> |
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#include <linux/uuid.h> |
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#include <linux/sysfs.h> |
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#include <linux/mdev.h> |
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#include "mdev_private.h" |
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#define DRIVER_VERSION "0.1" |
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#define DRIVER_AUTHOR "NVIDIA Corporation" |
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#define DRIVER_DESC "Mediated device Core Driver" |
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static LIST_HEAD(parent_list); |
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static DEFINE_MUTEX(parent_list_lock); |
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static struct class_compat *mdev_bus_compat_class; |
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static LIST_HEAD(mdev_list); |
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static DEFINE_MUTEX(mdev_list_lock); |
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struct device *mdev_parent_dev(struct mdev_device *mdev) |
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{ |
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return mdev->type->parent->dev; |
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} |
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EXPORT_SYMBOL(mdev_parent_dev); |
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/* |
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* Return the index in supported_type_groups that this mdev_device was created |
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* from. |
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*/ |
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unsigned int mdev_get_type_group_id(struct mdev_device *mdev) |
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{ |
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return mdev->type->type_group_id; |
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} |
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EXPORT_SYMBOL(mdev_get_type_group_id); |
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/* |
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* Used in mdev_type_attribute sysfs functions to return the index in the |
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* supported_type_groups that the sysfs is called from. |
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*/ |
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unsigned int mtype_get_type_group_id(struct mdev_type *mtype) |
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{ |
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return mtype->type_group_id; |
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} |
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EXPORT_SYMBOL(mtype_get_type_group_id); |
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/* |
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* Used in mdev_type_attribute sysfs functions to return the parent struct |
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* device |
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*/ |
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struct device *mtype_get_parent_dev(struct mdev_type *mtype) |
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{ |
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return mtype->parent->dev; |
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} |
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EXPORT_SYMBOL(mtype_get_parent_dev); |
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/* Should be called holding parent_list_lock */ |
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static struct mdev_parent *__find_parent_device(struct device *dev) |
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{ |
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struct mdev_parent *parent; |
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list_for_each_entry(parent, &parent_list, next) { |
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if (parent->dev == dev) |
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return parent; |
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} |
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return NULL; |
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} |
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void mdev_release_parent(struct kref *kref) |
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{ |
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struct mdev_parent *parent = container_of(kref, struct mdev_parent, |
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ref); |
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struct device *dev = parent->dev; |
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kfree(parent); |
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put_device(dev); |
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} |
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/* Caller must hold parent unreg_sem read or write lock */ |
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static void mdev_device_remove_common(struct mdev_device *mdev) |
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{ |
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struct mdev_parent *parent = mdev->type->parent; |
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int ret; |
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mdev_remove_sysfs_files(mdev); |
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device_del(&mdev->dev); |
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lockdep_assert_held(&parent->unreg_sem); |
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ret = parent->ops->remove(mdev); |
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if (ret) |
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dev_err(&mdev->dev, "Remove failed: err=%d\n", ret); |
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/* Balances with device_initialize() */ |
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put_device(&mdev->dev); |
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} |
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static int mdev_device_remove_cb(struct device *dev, void *data) |
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{ |
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struct mdev_device *mdev = mdev_from_dev(dev); |
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if (mdev) |
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mdev_device_remove_common(mdev); |
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return 0; |
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} |
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/* |
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* mdev_register_device : Register a device |
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* @dev: device structure representing parent device. |
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* @ops: Parent device operation structure to be registered. |
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* |
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* Add device to list of registered parent devices. |
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* Returns a negative value on error, otherwise 0. |
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*/ |
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int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops) |
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{ |
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int ret; |
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struct mdev_parent *parent; |
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char *env_string = "MDEV_STATE=registered"; |
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char *envp[] = { env_string, NULL }; |
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/* check for mandatory ops */ |
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if (!ops || !ops->create || !ops->remove || !ops->supported_type_groups) |
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return -EINVAL; |
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dev = get_device(dev); |
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if (!dev) |
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return -EINVAL; |
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/* Not mandatory, but its absence could be a problem */ |
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if (!ops->request) |
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dev_info(dev, "Driver cannot be asked to release device\n"); |
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mutex_lock(&parent_list_lock); |
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/* Check for duplicate */ |
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parent = __find_parent_device(dev); |
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if (parent) { |
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parent = NULL; |
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ret = -EEXIST; |
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goto add_dev_err; |
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} |
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parent = kzalloc(sizeof(*parent), GFP_KERNEL); |
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if (!parent) { |
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ret = -ENOMEM; |
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goto add_dev_err; |
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} |
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kref_init(&parent->ref); |
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init_rwsem(&parent->unreg_sem); |
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parent->dev = dev; |
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parent->ops = ops; |
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if (!mdev_bus_compat_class) { |
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mdev_bus_compat_class = class_compat_register("mdev_bus"); |
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if (!mdev_bus_compat_class) { |
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ret = -ENOMEM; |
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goto add_dev_err; |
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} |
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} |
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ret = parent_create_sysfs_files(parent); |
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if (ret) |
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goto add_dev_err; |
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ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL); |
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if (ret) |
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dev_warn(dev, "Failed to create compatibility class link\n"); |
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list_add(&parent->next, &parent_list); |
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mutex_unlock(&parent_list_lock); |
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dev_info(dev, "MDEV: Registered\n"); |
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kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp); |
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return 0; |
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add_dev_err: |
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mutex_unlock(&parent_list_lock); |
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if (parent) |
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mdev_put_parent(parent); |
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else |
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put_device(dev); |
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return ret; |
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} |
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EXPORT_SYMBOL(mdev_register_device); |
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/* |
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* mdev_unregister_device : Unregister a parent device |
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* @dev: device structure representing parent device. |
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* |
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* Remove device from list of registered parent devices. Give a chance to free |
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* existing mediated devices for given device. |
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*/ |
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void mdev_unregister_device(struct device *dev) |
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{ |
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struct mdev_parent *parent; |
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char *env_string = "MDEV_STATE=unregistered"; |
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char *envp[] = { env_string, NULL }; |
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mutex_lock(&parent_list_lock); |
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parent = __find_parent_device(dev); |
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if (!parent) { |
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mutex_unlock(&parent_list_lock); |
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return; |
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} |
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dev_info(dev, "MDEV: Unregistering\n"); |
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list_del(&parent->next); |
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mutex_unlock(&parent_list_lock); |
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down_write(&parent->unreg_sem); |
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class_compat_remove_link(mdev_bus_compat_class, dev, NULL); |
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device_for_each_child(dev, NULL, mdev_device_remove_cb); |
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parent_remove_sysfs_files(parent); |
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up_write(&parent->unreg_sem); |
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mdev_put_parent(parent); |
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/* We still have the caller's reference to use for the uevent */ |
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kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp); |
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} |
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EXPORT_SYMBOL(mdev_unregister_device); |
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static void mdev_device_release(struct device *dev) |
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{ |
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struct mdev_device *mdev = to_mdev_device(dev); |
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/* Pairs with the get in mdev_device_create() */ |
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kobject_put(&mdev->type->kobj); |
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mutex_lock(&mdev_list_lock); |
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list_del(&mdev->next); |
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mutex_unlock(&mdev_list_lock); |
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dev_dbg(&mdev->dev, "MDEV: destroying\n"); |
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kfree(mdev); |
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} |
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int mdev_device_create(struct mdev_type *type, const guid_t *uuid) |
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{ |
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int ret; |
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struct mdev_device *mdev, *tmp; |
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struct mdev_parent *parent = type->parent; |
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mutex_lock(&mdev_list_lock); |
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/* Check for duplicate */ |
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list_for_each_entry(tmp, &mdev_list, next) { |
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if (guid_equal(&tmp->uuid, uuid)) { |
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mutex_unlock(&mdev_list_lock); |
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return -EEXIST; |
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} |
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} |
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mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); |
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if (!mdev) { |
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mutex_unlock(&mdev_list_lock); |
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return -ENOMEM; |
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} |
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device_initialize(&mdev->dev); |
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mdev->dev.parent = parent->dev; |
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mdev->dev.bus = &mdev_bus_type; |
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mdev->dev.release = mdev_device_release; |
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mdev->dev.groups = parent->ops->mdev_attr_groups; |
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mdev->type = type; |
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/* Pairs with the put in mdev_device_release() */ |
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kobject_get(&type->kobj); |
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guid_copy(&mdev->uuid, uuid); |
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list_add(&mdev->next, &mdev_list); |
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mutex_unlock(&mdev_list_lock); |
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ret = dev_set_name(&mdev->dev, "%pUl", uuid); |
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if (ret) |
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goto out_put_device; |
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/* Check if parent unregistration has started */ |
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if (!down_read_trylock(&parent->unreg_sem)) { |
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ret = -ENODEV; |
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goto out_put_device; |
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} |
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ret = parent->ops->create(mdev); |
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if (ret) |
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goto out_unlock; |
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ret = device_add(&mdev->dev); |
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if (ret) |
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goto out_remove; |
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ret = mdev_create_sysfs_files(mdev); |
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if (ret) |
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goto out_del; |
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mdev->active = true; |
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dev_dbg(&mdev->dev, "MDEV: created\n"); |
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up_read(&parent->unreg_sem); |
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return 0; |
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out_del: |
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device_del(&mdev->dev); |
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out_remove: |
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parent->ops->remove(mdev); |
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out_unlock: |
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up_read(&parent->unreg_sem); |
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out_put_device: |
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put_device(&mdev->dev); |
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return ret; |
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} |
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int mdev_device_remove(struct mdev_device *mdev) |
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{ |
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struct mdev_device *tmp; |
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struct mdev_parent *parent = mdev->type->parent; |
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mutex_lock(&mdev_list_lock); |
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list_for_each_entry(tmp, &mdev_list, next) { |
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if (tmp == mdev) |
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break; |
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} |
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if (tmp != mdev) { |
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mutex_unlock(&mdev_list_lock); |
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return -ENODEV; |
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} |
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if (!mdev->active) { |
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mutex_unlock(&mdev_list_lock); |
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return -EAGAIN; |
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} |
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mdev->active = false; |
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mutex_unlock(&mdev_list_lock); |
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/* Check if parent unregistration has started */ |
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if (!down_read_trylock(&parent->unreg_sem)) |
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return -ENODEV; |
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mdev_device_remove_common(mdev); |
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up_read(&parent->unreg_sem); |
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return 0; |
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} |
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static int __init mdev_init(void) |
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{ |
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return mdev_bus_register(); |
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} |
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static void __exit mdev_exit(void) |
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{ |
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if (mdev_bus_compat_class) |
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class_compat_unregister(mdev_bus_compat_class); |
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mdev_bus_unregister(); |
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} |
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module_init(mdev_init) |
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module_exit(mdev_exit) |
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MODULE_VERSION(DRIVER_VERSION); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_AUTHOR(DRIVER_AUTHOR); |
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MODULE_DESCRIPTION(DRIVER_DESC); |
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MODULE_SOFTDEP("post: vfio_mdev");
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