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![Jason Gunthorpe](/assets/img/avatar_default.png)
Currently the driver ops have an open/release pair that is called once each time a device FD is opened or closed. Add an additional set of open/close_device() ops which are called when the device FD is opened for the first time and closed for the last time. An analysis shows that all of the drivers require this semantic. Some are open coding it as part of their reflck implementation, and some are just buggy and miss it completely. To retain the current semantics PCI and FSL depend on, introduce the idea of a "device set" which is a grouping of vfio_device's that share the same lock around opening. The device set is established by providing a 'set_id' pointer. All vfio_device's that provide the same pointer will be joined to the same singleton memory and lock across the whole set. This effectively replaces the oddly named reflck. After conversion the set_id will be sourced from: - A struct device from a fsl_mc_device (fsl) - A struct pci_slot (pci) - A struct pci_bus (pci) - The struct vfio_device (everything) The design ensures that the above pointers are live as long as the vfio_device is registered, so they form reliable unique keys to group vfio_devices into sets. This implementation uses xarray instead of searching through the driver core structures, which simplifies the somewhat tricky locking in this area. Following patches convert all the drivers. Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/4-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
192 lines
6.2 KiB
C
192 lines
6.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Mediated device definition
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*
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* Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
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* Author: Neo Jia <cjia@nvidia.com>
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* Kirti Wankhede <kwankhede@nvidia.com>
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*/
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#ifndef MDEV_H
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#define MDEV_H
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struct mdev_type;
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struct mdev_device {
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struct device dev;
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guid_t uuid;
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void *driver_data;
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struct list_head next;
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struct mdev_type *type;
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struct device *iommu_device;
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bool active;
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};
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static inline struct mdev_device *to_mdev_device(struct device *dev)
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{
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return container_of(dev, struct mdev_device, dev);
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}
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/*
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* Called by the parent device driver to set the device which represents
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* this mdev in iommu protection scope. By default, the iommu device is
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* NULL, that indicates using vendor defined isolation.
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*
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* @dev: the mediated device that iommu will isolate.
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* @iommu_device: a pci device which represents the iommu for @dev.
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*/
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static inline void mdev_set_iommu_device(struct mdev_device *mdev,
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struct device *iommu_device)
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{
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mdev->iommu_device = iommu_device;
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}
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static inline struct device *mdev_get_iommu_device(struct mdev_device *mdev)
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{
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return mdev->iommu_device;
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}
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unsigned int mdev_get_type_group_id(struct mdev_device *mdev);
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unsigned int mtype_get_type_group_id(struct mdev_type *mtype);
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struct device *mtype_get_parent_dev(struct mdev_type *mtype);
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/**
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* struct mdev_parent_ops - Structure to be registered for each parent device to
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* register the device to mdev module.
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*
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* @owner: The module owner.
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* @device_driver: Which device driver to probe() on newly created devices
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* @dev_attr_groups: Attributes of the parent device.
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* @mdev_attr_groups: Attributes of the mediated device.
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* @supported_type_groups: Attributes to define supported types. It is mandatory
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* to provide supported types.
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* @create: Called to allocate basic resources in parent device's
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* driver for a particular mediated device. It is
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* mandatory to provide create ops.
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* @mdev: mdev_device structure on of mediated device
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* that is being created
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* Returns integer: success (0) or error (< 0)
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* @remove: Called to free resources in parent device's driver for
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* a mediated device. It is mandatory to provide 'remove'
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* ops.
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* @mdev: mdev_device device structure which is being
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* destroyed
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* Returns integer: success (0) or error (< 0)
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* @open: Open mediated device.
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* @mdev: mediated device.
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* Returns integer: success (0) or error (< 0)
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* @release: release mediated device
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* @mdev: mediated device.
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* @read: Read emulation callback
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* @mdev: mediated device structure
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* @buf: read buffer
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* @count: number of bytes to read
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* @ppos: address.
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* Retuns number on bytes read on success or error.
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* @write: Write emulation callback
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* @mdev: mediated device structure
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* @buf: write buffer
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* @count: number of bytes to be written
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* @ppos: address.
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* Retuns number on bytes written on success or error.
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* @ioctl: IOCTL callback
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* @mdev: mediated device structure
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* @cmd: ioctl command
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* @arg: arguments to ioctl
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* @mmap: mmap callback
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* @mdev: mediated device structure
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* @vma: vma structure
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* @request: request callback to release device
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* @mdev: mediated device structure
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* @count: request sequence number
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* Parent device that support mediated device should be registered with mdev
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* module with mdev_parent_ops structure.
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**/
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struct mdev_parent_ops {
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struct module *owner;
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struct mdev_driver *device_driver;
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const struct attribute_group **dev_attr_groups;
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const struct attribute_group **mdev_attr_groups;
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struct attribute_group **supported_type_groups;
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int (*create)(struct mdev_device *mdev);
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int (*remove)(struct mdev_device *mdev);
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int (*open_device)(struct mdev_device *mdev);
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void (*close_device)(struct mdev_device *mdev);
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int (*open)(struct mdev_device *mdev);
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void (*release)(struct mdev_device *mdev);
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ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
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size_t count, loff_t *ppos);
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ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
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size_t count, loff_t *ppos);
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long (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
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unsigned long arg);
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int (*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
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void (*request)(struct mdev_device *mdev, unsigned int count);
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};
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/* interface for exporting mdev supported type attributes */
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struct mdev_type_attribute {
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struct attribute attr;
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ssize_t (*show)(struct mdev_type *mtype,
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struct mdev_type_attribute *attr, char *buf);
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ssize_t (*store)(struct mdev_type *mtype,
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struct mdev_type_attribute *attr, const char *buf,
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size_t count);
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};
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#define MDEV_TYPE_ATTR(_name, _mode, _show, _store) \
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struct mdev_type_attribute mdev_type_attr_##_name = \
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__ATTR(_name, _mode, _show, _store)
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#define MDEV_TYPE_ATTR_RW(_name) \
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struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RW(_name)
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#define MDEV_TYPE_ATTR_RO(_name) \
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struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
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#define MDEV_TYPE_ATTR_WO(_name) \
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struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name)
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/**
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* struct mdev_driver - Mediated device driver
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* @probe: called when new device created
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* @remove: called when device removed
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* @driver: device driver structure
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*
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**/
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struct mdev_driver {
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int (*probe)(struct mdev_device *dev);
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void (*remove)(struct mdev_device *dev);
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struct device_driver driver;
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};
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static inline void *mdev_get_drvdata(struct mdev_device *mdev)
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{
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return mdev->driver_data;
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}
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static inline void mdev_set_drvdata(struct mdev_device *mdev, void *data)
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{
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mdev->driver_data = data;
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}
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static inline const guid_t *mdev_uuid(struct mdev_device *mdev)
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{
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return &mdev->uuid;
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}
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extern struct bus_type mdev_bus_type;
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int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops);
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void mdev_unregister_device(struct device *dev);
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int mdev_register_driver(struct mdev_driver *drv);
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void mdev_unregister_driver(struct mdev_driver *drv);
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struct device *mdev_parent_dev(struct mdev_device *mdev);
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static inline struct device *mdev_dev(struct mdev_device *mdev)
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{
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return &mdev->dev;
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}
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static inline struct mdev_device *mdev_from_dev(struct device *dev)
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{
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return dev->bus == &mdev_bus_type ? to_mdev_device(dev) : NULL;
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}
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#endif /* MDEV_H */
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