diff options
| author | Jason Gunthorpe <jgg@nvidia.com> | 2021-03-30 09:53:08 -0600 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2021-04-06 11:55:11 -0600 |
| commit | 6df62c5b05f4ad6876815ea8b8775905a090224a (patch) | |
| tree | 5573ffa1f6aa10a74d807b9bb161fc188885af41 /Documentation/driver-api | |
| parent | 66873b5fa738ca02b5c075ca4a410b13d88e6e9a (diff) | |
vfio: Make vfio_device_ops pass a 'struct vfio_device *' instead of 'void *'
This is the standard kernel pattern, the ops associated with a struct get
the struct pointer in for typesafety. The expected design is to use
container_of to cleanly go from the subsystem level type to the driver
level type without having any type erasure in a void *.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <12-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'Documentation/driver-api')
| -rw-r--r-- | Documentation/driver-api/vfio.rst | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/Documentation/driver-api/vfio.rst b/Documentation/driver-api/vfio.rst index d3a02300913a..3337f337293a 100644 --- a/Documentation/driver-api/vfio.rst +++ b/Documentation/driver-api/vfio.rst @@ -269,20 +269,22 @@ ready before calling it. The driver provides an ops structure for callbacks similar to a file operations structure:: struct vfio_device_ops { - int (*open)(void *device_data); - void (*release)(void *device_data); - ssize_t (*read)(void *device_data, char __user *buf, + int (*open)(struct vfio_device *vdev); + void (*release)(struct vfio_device *vdev); + ssize_t (*read)(struct vfio_device *vdev, char __user *buf, size_t count, loff_t *ppos); - ssize_t (*write)(void *device_data, const char __user *buf, + ssize_t (*write)(struct vfio_device *vdev, + const char __user *buf, size_t size, loff_t *ppos); - long (*ioctl)(void *device_data, unsigned int cmd, + long (*ioctl)(struct vfio_device *vdev, unsigned int cmd, unsigned long arg); - int (*mmap)(void *device_data, struct vm_area_struct *vma); + int (*mmap)(struct vfio_device *vdev, + struct vm_area_struct *vma); }; -Each function is passed the device_data that was originally registered +Each function is passed the vdev that was originally registered in the vfio_register_group_dev() call above. This allows the bus driver -an easy place to store its opaque, private data. The open/release +to obtain its private data using container_of(). The open/release callbacks are issued when a new file descriptor is created for a device (via VFIO_GROUP_GET_DEVICE_FD). The ioctl interface provides a direct pass through for VFIO_DEVICE_* ioctls. The read/write/mmap |