include/linux/mdev.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Mediated device definition
   4  *
   5  * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
   6  *     Author: Neo Jia <cjia@nvidia.com>
   7  *             Kirti Wankhede <kwankhede@nvidia.com>
   8  */
   9
  10 #ifndef MDEV_H
  11 #define MDEV_H
  12
  13 #include <linux/device.h>
  14 #include <linux/uuid.h>
  15
  16 struct mdev_type;
  17
  18 struct mdev_device {
  19         struct device dev;
  20         guid_t uuid;
  21         struct list_head next;
  22         struct mdev_type *type;
  23         bool active;
  24 };
  25
  26 struct mdev_type {
  27         /* set by the driver before calling mdev_register parent: */
  28         const char *sysfs_name;
  29         const char *pretty_name;
  30
  31         /* set by the core, can be used drivers */
  32         struct mdev_parent *parent;
  33
  34         /* internal only */
  35         struct kobject kobj;
  36         struct kobject *devices_kobj;
  37 };
  38
  39 /* embedded into the struct device that the mdev devices hang off */
  40 struct mdev_parent {
  41         struct device *dev;
  42         struct mdev_driver *mdev_driver;
  43         struct kset *mdev_types_kset;
  44         /* Synchronize device creation/removal with parent unregistration */
  45         struct rw_semaphore unreg_sem;
  46         struct mdev_type **types;
  47         unsigned int nr_types;
  48         atomic_t available_instances;
  49 };
  50
  51 static inline struct mdev_device *to_mdev_device(struct device *dev)
  52 {
  53         return container_of(dev, struct mdev_device, dev);
  54 }
  55
  56 /**
  57  * struct mdev_driver - Mediated device driver
  58  * @device_api: string to return for the device_api sysfs
  59  * @max_instances: maximum number of instances supported (optional)
  60  * @probe: called when new device created
  61  * @remove: called when device removed
  62  * @get_available: Return the max number of instances that can be created
  63  * @show_description: Print a description of the mtype
  64  * @driver: device driver structure
  65  **/
  66 struct mdev_driver {
  67         const char *device_api;
  68         unsigned int max_instances;
  69         int (*probe)(struct mdev_device *dev);
  70         void (*remove)(struct mdev_device *dev);
  71         unsigned int (*get_available)(struct mdev_type *mtype);
  72         ssize_t (*show_description)(struct mdev_type *mtype, char *buf);
  73         struct device_driver driver;
  74 };
  75
  76 int mdev_register_parent(struct mdev_parent *parent, struct device *dev,
  77                 struct mdev_driver *mdev_driver, struct mdev_type **types,
  78                 unsigned int nr_types);
  79 void mdev_unregister_parent(struct mdev_parent *parent);
  80
  81 int mdev_register_driver(struct mdev_driver *drv);
  82 void mdev_unregister_driver(struct mdev_driver *drv);
  83
  84 static inline struct device *mdev_dev(struct mdev_device *mdev)
  85 {
  86         return &mdev->dev;
  87 }
  88
  89 #endif /* MDEV_H */