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 /* Mediated device */
  17 struct mdev_device {
  18         struct device           dev;
  19         struct mdev_parent      *parent;
  20         uuid_le                 uuid;
  21         void                    *driver_data;
  22
  23         /* internal */
  24         struct kref             ref;
  25         struct list_head        next;
  26         struct kobject          *type_kobj;
  27 };
  28
  29 /**
  30  * struct mdev_parent_ops - Structure to be registered for each parent device to
  31  * register the device to mdev module.
  32  *
  33  * @owner:              The module owner.
  34  * @dev_attr_groups:    Attributes of the parent device.
  35  * @mdev_attr_groups:   Attributes of the mediated device.
  36  * @supported_type_groups: Attributes to define supported types. It is mandatory
  37  *                      to provide supported types.
  38  * @create:             Called to allocate basic resources in parent device's
  39  *                      driver for a particular mediated device. It is
  40  *                      mandatory to provide create ops.
  41  *                      @kobj: kobject of type for which 'create' is called.
  42  *                      @mdev: mdev_device structure on of mediated device
  43  *                            that is being created
  44  *                      Returns integer: success (0) or error (< 0)
  45  * @remove:             Called to free resources in parent device's driver for a
  46  *                      a mediated device. It is mandatory to provide 'remove'
  47  *                      ops.
  48  *                      @mdev: mdev_device device structure which is being
  49  *                             destroyed
  50  *                      Returns integer: success (0) or error (< 0)
  51  * @open:               Open mediated device.
  52  *                      @mdev: mediated device.
  53  *                      Returns integer: success (0) or error (< 0)
  54  * @release:            release mediated device
  55  *                      @mdev: mediated device.
  56  * @read:               Read emulation callback
  57  *                      @mdev: mediated device structure
  58  *                      @buf: read buffer
  59  *                      @count: number of bytes to read
  60  *                      @ppos: address.
  61  *                      Retuns number on bytes read on success or error.
  62  * @write:              Write emulation callback
  63  *                      @mdev: mediated device structure
  64  *                      @buf: write buffer
  65  *                      @count: number of bytes to be written
  66  *                      @ppos: address.
  67  *                      Retuns number on bytes written on success or error.
  68  * @ioctl:              IOCTL callback
  69  *                      @mdev: mediated device structure
  70  *                      @cmd: ioctl command
  71  *                      @arg: arguments to ioctl
  72  * @mmap:               mmap callback
  73  *                      @mdev: mediated device structure
  74  *                      @vma: vma structure
  75  * Parent device that support mediated device should be registered with mdev
  76  * module with mdev_parent_ops structure.
  77  **/
  78
  79 struct mdev_parent_ops {
  80         struct module   *owner;
  81         const struct attribute_group **dev_attr_groups;
  82         const struct attribute_group **mdev_attr_groups;
  83         struct attribute_group **supported_type_groups;
  84
  85         int     (*create)(struct kobject *kobj, struct mdev_device *mdev);
  86         int     (*remove)(struct mdev_device *mdev);
  87         int     (*open)(struct mdev_device *mdev);
  88         void    (*release)(struct mdev_device *mdev);
  89         ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
  90                         size_t count, loff_t *ppos);
  91         ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
  92                          size_t count, loff_t *ppos);
  93         ssize_t (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
  94                          unsigned long arg);
  95         int     (*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
  96 };
  97
  98 /* interface for exporting mdev supported type attributes */
  99 struct mdev_type_attribute {
 100         struct attribute attr;
 101         ssize_t (*show)(struct kobject *kobj, struct device *dev, char *buf);
 102         ssize_t (*store)(struct kobject *kobj, struct device *dev,
 103                          const char *buf, size_t count);
 104 };
 105
 106 #define MDEV_TYPE_ATTR(_name, _mode, _show, _store)             \
 107 struct mdev_type_attribute mdev_type_attr_##_name =             \
 108         __ATTR(_name, _mode, _show, _store)
 109 #define MDEV_TYPE_ATTR_RW(_name) \
 110         struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RW(_name)
 111 #define MDEV_TYPE_ATTR_RO(_name) \
 112         struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
 113 #define MDEV_TYPE_ATTR_WO(_name) \
 114         struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name)
 115
 116 /**
 117  * struct mdev_driver - Mediated device driver
 118  * @name: driver name
 119  * @probe: called when new device created
 120  * @remove: called when device removed
 121  * @driver: device driver structure
 122  *
 123  **/
 124 struct mdev_driver {
 125         const char *name;
 126         int  (*probe)(struct device *dev);
 127         void (*remove)(struct device *dev);
 128         struct device_driver driver;
 129 };
 130
 131 #define to_mdev_driver(drv)     container_of(drv, struct mdev_driver, driver)
 132 #define to_mdev_device(dev)     container_of(dev, struct mdev_device, dev)
 133
 134 static inline void *mdev_get_drvdata(struct mdev_device *mdev)
 135 {
 136         return mdev->driver_data;
 137 }
 138
 139 static inline void mdev_set_drvdata(struct mdev_device *mdev, void *data)
 140 {
 141         mdev->driver_data = data;
 142 }
 143
 144 extern struct bus_type mdev_bus_type;
 145
 146 #define dev_is_mdev(d) ((d)->bus == &mdev_bus_type)
 147
 148 extern int  mdev_register_device(struct device *dev,
 149                                  const struct mdev_parent_ops *ops);
 150 extern void mdev_unregister_device(struct device *dev);
 151
 152 extern int  mdev_register_driver(struct mdev_driver *drv, struct module *owner);
 153 extern void mdev_unregister_driver(struct mdev_driver *drv);
 154
 155 extern struct device *mdev_parent_dev(struct mdev_device *mdev);
 156
 157 #endif /* MDEV_H */