drivers/vfio/mdev/mdev_driver.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * MDEV driver
   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 #include <linux/iommu.h>
  11 #include <linux/mdev.h>
  12
  13 #include "mdev_private.h"
  14
  15 static int mdev_probe(struct device *dev)
  16 {
  17         struct mdev_driver *drv =
  18                 container_of(dev->driver, struct mdev_driver, driver);
  19
  20         if (!drv->probe)
  21                 return 0;
  22         return drv->probe(to_mdev_device(dev));
  23 }
  24
  25 static void mdev_remove(struct device *dev)
  26 {
  27         struct mdev_driver *drv =
  28                 container_of(dev->driver, struct mdev_driver, driver);
  29
  30         if (drv->remove)
  31                 drv->remove(to_mdev_device(dev));
  32 }
  33
  34 static int mdev_match(struct device *dev, struct device_driver *drv)
  35 {
  36         /*
  37          * No drivers automatically match. Drivers are only bound by explicit
  38          * device_driver_attach()
  39          */
  40         return 0;
  41 }
  42
  43 const struct bus_type mdev_bus_type = {
  44         .name           = "mdev",
  45         .probe          = mdev_probe,
  46         .remove         = mdev_remove,
  47         .match          = mdev_match,
  48 };
  49
  50 /**
  51  * mdev_register_driver - register a new MDEV driver
  52  * @drv: the driver to register
  53  *
  54  * Returns a negative value on error, otherwise 0.
  55  **/
  56 int mdev_register_driver(struct mdev_driver *drv)
  57 {
  58         if (!drv->device_api)
  59                 return -EINVAL;
  60
  61         /* initialize common driver fields */
  62         drv->driver.bus = &mdev_bus_type;
  63         return driver_register(&drv->driver);
  64 }
  65 EXPORT_SYMBOL(mdev_register_driver);
  66
  67 /*
  68  * mdev_unregister_driver - unregister MDEV driver
  69  * @drv: the driver to unregister
  70  */
  71 void mdev_unregister_driver(struct mdev_driver *drv)
  72 {
  73         driver_unregister(&drv->driver);
  74 }
  75 EXPORT_SYMBOL(mdev_unregister_driver);