include/linux/mdev.h

   1 /*
   2  * Mediated device definition
   3  *
   4  * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
   5  *     Author: Neo Jia <cjia@nvidia.com>
   6  *             Kirti Wankhede <kwankhede@nvidia.com>
   7  *
   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.
  11  */
  12
  13 #ifndef MDEV_H
  14 #define MDEV_H
  15
  16 struct mdev_device;
  17
  18 /**
  19  * struct mdev_parent_ops - Structure to be registered for each parent device to
  20  * register the device to mdev module.
  21  *
  22  * @owner:              The module owner.
  23  * @dev_attr_groups:    Attributes of the parent device.
  24  * @mdev_attr_groups:   Attributes of the mediated device.
  25  * @supported_type_groups: Attributes to define supported types. It is mandatory
  26  *                      to provide supported types.
  27  * @create:             Called to allocate basic resources in parent device's
  28  *                      driver for a particular mediated device. It is
  29  *                      mandatory to provide create ops.
  30  *                      @kobj: kobject of type for which 'create' is called.
  31  *                      @mdev: mdev_device structure on of mediated device
  32  *                            that is being created
  33  *                      Returns integer: success (0) or error (< 0)
  34  * @remove:             Called to free resources in parent device's driver for a
  35  *                      a mediated device. It is mandatory to provide 'remove'
  36  *                      ops.
  37  *                      @mdev: mdev_device device structure which is being
  38  *                             destroyed
  39  *                      Returns integer: success (0) or error (< 0)
  40  * @open:               Open mediated device.
  41  *                      @mdev: mediated device.
  42  *                      Returns integer: success (0) or error (< 0)
  43  * @release:            release mediated device
  44  *                      @mdev: mediated device.
  45  * @read:               Read emulation callback
  46  *                      @mdev: mediated device structure
  47  *                      @buf: read buffer
  48  *                      @count: number of bytes to read
  49  *                      @ppos: address.
  50  *                      Retuns number on bytes read on success or error.
  51  * @write:              Write emulation callback
  52  *                      @mdev: mediated device structure
  53  *                      @buf: write buffer
  54  *                      @count: number of bytes to be written
  55  *                      @ppos: address.
  56  *                      Retuns number on bytes written on success or error.
  57  * @ioctl:              IOCTL callback
  58  *                      @mdev: mediated device structure
  59  *                      @cmd: ioctl command
  60  *                      @arg: arguments to ioctl
  61  * @mmap:               mmap callback
  62  *                      @mdev: mediated device structure
  63  *                      @vma: vma structure
  64  * Parent device that support mediated device should be registered with mdev
  65  * module with mdev_parent_ops structure.
  66  **/
  67 struct mdev_parent_ops {
  68         struct module   *owner;
  69         const struct attribute_group **dev_attr_groups;
  70         const struct attribute_group **mdev_attr_groups;
  71         struct attribute_group **supported_type_groups;
  72
  73         int     (*create)(struct kobject *kobj, struct mdev_device *mdev);
  74         int     (*remove)(struct mdev_device *mdev);
  75         int     (*open)(struct mdev_device *mdev);
  76         void    (*release)(struct mdev_device *mdev);
  77         ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
  78                         size_t count, loff_t *ppos);
  79         ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
  80                          size_t count, loff_t *ppos);
  81         long    (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
  82                          unsigned long arg);
  83         int     (*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
  84 };
  85
  86 /* interface for exporting mdev supported type attributes */
  87 struct mdev_type_attribute {
  88         struct attribute attr;
  89         ssize_t (*show)(struct kobject *kobj, struct device *dev, char *buf);
  90         ssize_t (*store)(struct kobject *kobj, struct device *dev,
  91                          const char *buf, size_t count);
  92 };
  93
  94 #define MDEV_TYPE_ATTR(_name, _mode, _show, _store)             \
  95 struct mdev_type_attribute mdev_type_attr_##_name =             \
  96         __ATTR(_name, _mode, _show, _store)
  97 #define MDEV_TYPE_ATTR_RW(_name) \
  98         struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RW(_name)
  99 #define MDEV_TYPE_ATTR_RO(_name) \
 100         struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
 101 #define MDEV_TYPE_ATTR_WO(_name) \
 102         struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name)
 103
 104 /**
 105  * struct mdev_driver - Mediated device driver
 106  * @name: driver name
 107  * @probe: called when new device created
 108  * @remove: called when device removed
 109  * @driver: device driver structure
 110  *
 111  **/
 112 struct mdev_driver {
 113         const char *name;
 114         int  (*probe)(struct device *dev);
 115         void (*remove)(struct device *dev);
 116         struct device_driver driver;
 117 };
 118
 119 #define to_mdev_driver(drv)     container_of(drv, struct mdev_driver, driver)
 120
 121 extern void *mdev_get_drvdata(struct mdev_device *mdev);
 122 extern void mdev_set_drvdata(struct mdev_device *mdev, void *data);
 123 extern uuid_le mdev_uuid(struct mdev_device *mdev);
 124
 125 extern struct bus_type mdev_bus_type;
 126
 127 extern int  mdev_register_device(struct device *dev,
 128                                  const struct mdev_parent_ops *ops);
 129 extern void mdev_unregister_device(struct device *dev);
 130
 131 extern int  mdev_register_driver(struct mdev_driver *drv, struct module *owner);
 132 extern void mdev_unregister_driver(struct mdev_driver *drv);
 133
 134 extern struct device *mdev_parent_dev(struct mdev_device *mdev);
 135 extern struct device *mdev_dev(struct mdev_device *mdev);
 136 extern struct mdev_device *mdev_from_dev(struct device *dev);
 137
 138 #endif /* MDEV_H */