On Tue, Dec 02, 2025 at 05:03:30PM -0500, Lyude Paul wrote:
> This is an associated type that may be used in order to specify a data-type
> to pass to gem objects when construction them, allowing for drivers to more
> easily initialize their private-data for gem objects.
>
> Signed-off-by: Lyude Paul <[email protected]>
> Reviewed-by: Alice Ryhl <[email protected]>
> Reviewed-by: Daniel Almeida <[email protected]>
>
> ---
> V3:
> * s/BaseDriverObject/DriverObject/
> V4:
> * Fix leftover reference to BaseObjectDriver in rustdoc for
> DriverObject::Args
> V6:
> * Fix build errors in Tyr
>
> drivers/gpu/drm/nova/gem.rs | 5 +++--
> drivers/gpu/drm/tyr/gem.rs | 3 ++-
> rust/kernel/drm/gem/mod.rs | 13 ++++++++++---
> 3 files changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/nova/gem.rs b/drivers/gpu/drm/nova/gem.rs
> index 2760ba4f3450b..173077eeb2def 100644
> --- a/drivers/gpu/drm/nova/gem.rs
> +++ b/drivers/gpu/drm/nova/gem.rs
> @@ -18,8 +18,9 @@ pub(crate) struct NovaObject {}
>
> impl gem::DriverObject for NovaObject {
> type Driver = NovaDriver;
> + type Args = ();
>
> - fn new(_dev: &NovaDevice, _size: usize) -> impl PinInit<Self, Error> {
> + fn new(_dev: &NovaDevice, _size: usize, _args: Self::Args) -> impl
> PinInit<Self, Error> {
> try_pin_init!(NovaObject {})
> }
> }
> @@ -33,7 +34,7 @@ pub(crate) fn new(dev: &NovaDevice, size: usize) ->
> Result<ARef<gem::Object<Self
> return Err(EINVAL);
> }
>
> - gem::Object::new(dev, aligned_size)
> + gem::Object::new(dev, aligned_size, ())
> }
>
> /// Look up a GEM object handle for a `File` and return an `ObjectRef`
> for it.
> diff --git a/drivers/gpu/drm/tyr/gem.rs b/drivers/gpu/drm/tyr/gem.rs
> index 1273bf89dbd5d..bb5e7871efa94 100644
> --- a/drivers/gpu/drm/tyr/gem.rs
> +++ b/drivers/gpu/drm/tyr/gem.rs
> @@ -11,8 +11,9 @@ pub(crate) struct TyrObject {}
>
> impl gem::DriverObject for TyrObject {
> type Driver = TyrDriver;
> + type Args = ();
>
> - fn new(_dev: &TyrDevice, _size: usize) -> impl PinInit<Self, Error> {
> + fn new(_dev: &TyrDevice, _size: usize, _args: ()) -> impl PinInit<Self,
> Error> {
nit: should the type for _args be Self::Args for consistency?
> try_pin_init!(TyrObject {})
> }
> }
> diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
> index ec3c1b1775196..4bcaee2d4b308 100644
> --- a/rust/kernel/drm/gem/mod.rs
> +++ b/rust/kernel/drm/gem/mod.rs
> @@ -64,8 +64,15 @@ pub trait DriverObject: Sync + Send + Sized {
> /// Parent `Driver` for this object.
> type Driver: drm::Driver;
>
> + /// The data type to use for passing arguments to [`DriverObject::new`].
> + type Args;
> +
> /// Create a new driver data object for a GEM object of a given size.
> - fn new(dev: &drm::Device<Self::Driver>, size: usize) -> impl
> PinInit<Self, Error>;
> + fn new(
> + dev: &drm::Device<Self::Driver>,
> + size: usize,
> + args: Self::Args,
> + ) -> impl PinInit<Self, Error>;
>
> /// Open a new handle to an existing object, associated with a File.
> fn open(_obj: &<Self::Driver as drm::Driver>::Object, _file:
> &DriverFile<Self>) -> Result {
> @@ -244,11 +251,11 @@ impl<T: DriverObject> Object<T> {
> };
>
> /// Create a new GEM object.
> - pub fn new(dev: &drm::Device<T::Driver>, size: usize) ->
> Result<ARef<Self>> {
> + pub fn new(dev: &drm::Device<T::Driver>, size: usize, args: T::Args) ->
> Result<ARef<Self>> {
> let obj: Pin<KBox<Self>> = KBox::pin_init(
> try_pin_init!(Self {
> obj: Opaque::new(bindings::drm_gem_object::default()),
> - data <- T::new(dev, size),
> + data <- T::new(dev, size, args),
> }),
> GFP_KERNEL,
> )?;
> --
> 2.52.0
Reviewed-by: Janne Grunau <[email protected]>
Janne
