forked from mirrors/linux
9c799c224d
Many of the mdev drivers use a simple counter for keeping track of the available instances. Move this code to the core code and store the counter in the mdev_parent. Implement it using correct locking, fixing mdpy. Drivers just provide the value in the mdev_driver at registration time and the core code takes care of maintaining it and exposing the value in sysfs. [hch: count instances per-parent instead of per-type, use an atomic_t to avoid taking mdev_list_lock in the show method] Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Link: https://lore.kernel.org/r/20220923092652.100656-15-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
89 lines
2.4 KiB
C
89 lines
2.4 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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#include <linux/device.h>
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#include <linux/uuid.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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struct list_head next;
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struct mdev_type *type;
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bool active;
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};
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struct mdev_type {
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/* set by the driver before calling mdev_register parent: */
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const char *sysfs_name;
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const char *pretty_name;
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/* set by the core, can be used drivers */
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struct mdev_parent *parent;
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/* internal only */
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struct kobject kobj;
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struct kobject *devices_kobj;
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};
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/* embedded into the struct device that the mdev devices hang off */
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struct mdev_parent {
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struct device *dev;
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struct mdev_driver *mdev_driver;
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struct kset *mdev_types_kset;
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/* Synchronize device creation/removal with parent unregistration */
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struct rw_semaphore unreg_sem;
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struct mdev_type **types;
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unsigned int nr_types;
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atomic_t available_instances;
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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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* struct mdev_driver - Mediated device driver
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* @device_api: string to return for the device_api sysfs
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* @max_instances: maximum number of instances supported (optional)
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* @probe: called when new device created
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* @remove: called when device removed
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* @get_available: Return the max number of instances that can be created
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* @show_description: Print a description of the mtype
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* @driver: device driver structure
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**/
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struct mdev_driver {
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const char *device_api;
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unsigned int max_instances;
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int (*probe)(struct mdev_device *dev);
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void (*remove)(struct mdev_device *dev);
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unsigned int (*get_available)(struct mdev_type *mtype);
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ssize_t (*show_description)(struct mdev_type *mtype, char *buf);
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struct device_driver driver;
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};
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int mdev_register_parent(struct mdev_parent *parent, struct device *dev,
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struct mdev_driver *mdev_driver, struct mdev_type **types,
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unsigned int nr_types);
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void mdev_unregister_parent(struct mdev_parent *parent);
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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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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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#endif /* MDEV_H */
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