Re: [PATCH v6 1/7] drm/tyr: add resources to RegistrationData

[Daniel Almeida <daniel.almeida@collabora.com>]

> On 9 Jul 2026, at 18:36, Deborah Brouwer <deborah.brouwer@collabora.com> wrote:
> 
> Currently Tyr is not storing any resources in its drm::Driver
> RegistrationData.
> 
> Move Tyr's device-private resources and gpu information from
> drm::Driver::Data to drm::Driver::RegistrationData. This allows Tyr to
> access this data safely within the lifetime of its binding to its parent
> platform device and while registered with userspace.
> 
> Signed-off-by: Deborah Brouwer <deborah.brouwer@collabora.com>
> ---
> drivers/gpu/drm/tyr/driver.rs | 42 +++++++++++++++++++++---------------------
> drivers/gpu/drm/tyr/file.rs   | 11 ++++++-----
> 2 files changed, 27 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/gpu/drm/tyr/driver.rs b/drivers/gpu/drm/tyr/driver.rs
> index 8348c6cd3929..46ce5c41e310 100644
> --- a/drivers/gpu/drm/tyr/driver.rs
> +++ b/drivers/gpu/drm/tyr/driver.rs
> @@ -6,6 +6,7 @@
>         OptionalClk, //
>     },
>     device::{
> +        Bound,
>         Core,
>         Device,
>         DeviceContext, //
> @@ -27,10 +28,7 @@
>     regulator,
>     regulator::Regulator,
>     sizes::SZ_2M,
> -    sync::{
> -        aref::ARef,
> -        Mutex, //
> -    },
> +    sync::Mutex,
>     time, //
> };
> 
> @@ -53,13 +51,17 @@
> 
> #[pin_data(PinnedDrop)]
> pub(crate) struct TyrPlatformDriverData<'bound> {
> -    _device: ARef<TyrDrmDevice>,
>     _reg: drm::Registration<'bound, TyrDrmDriver>,
> }
> 
> +/// Data owned by the DRM [`Registration`].
> +///
> +/// This data can have references tied to the parent platform device binding scope
> +/// and is accessible only while the DRM device is registered with userspace.
> #[pin_data]
> -pub(crate) struct TyrDrmDeviceData {
> -    pub(crate) pdev: ARef<platform::Device>,
> +pub(crate) struct TyrDrmRegistrationData<'bound> {
> +    /// Parent platform device.
> +    pub(crate) pdev: &'bound platform::Device<Bound>,
> 
>     #[pin]
>     clks: Mutex<Clocks>,
> @@ -67,9 +69,10 @@ pub(crate) struct TyrDrmDeviceData {
>     #[pin]
>     regulators: Mutex<Regulators>,
> 
> -    /// Some information on the GPU.
> -    ///
> -    /// This is mainly queried by userspace, i.e.: Mesa.
> +    /// GPU MMIO register mapping.
> +    pub(crate) iomem: IoMem<'bound>,
> +
> +    /// GPU information read from hardware during probe.
>     pub(crate) gpu_info: GpuInfo,
> }
> 
> @@ -134,10 +137,10 @@ fn probe<'bound>(
>         // other threads of execution.
>         unsafe { pdev.dma_set_mask_and_coherent(DmaMask::try_new(pa_bits)?)? };
> 
> -        let platform: ARef<platform::Device> = pdev.into();
> +        let unreg_dev = drm::UnregisteredDevice::<TyrDrmDriver>::new(pdev, Ok(()))?;
> 
> -        let data = try_pin_init!(TyrDrmDeviceData {
> -                pdev: platform.clone(),
> +        let reg_data = try_pin_init!(TyrDrmRegistrationData {
> +                pdev,
>                 clks <- new_mutex!(Clocks {
>                     core: core_clk,
>                     stacks: stacks_clk,
> @@ -147,18 +150,15 @@ fn probe<'bound>(
>                     _mali: mali_regulator,
>                     _sram: sram_regulator,
>                 }),
> +                iomem,
>                 gpu_info,
>         });
> 
> -        let tdev = drm::UnregisteredDevice::<TyrDrmDriver>::new(pdev, data)?;
>         // SAFETY: `reg` is stored in `TyrPlatformDriverData` and dropped when the driver is
>         // unbound; it is never forgotten.
> -        let reg = unsafe { drm::Registration::new(pdev.as_ref(), tdev, (), 0)? };
> +        let reg = unsafe { drm::Registration::new(pdev.as_ref(), unreg_dev, reg_data, 0)? };
> 
> -        let driver = TyrPlatformDriverData {
> -            _device: reg.device().into(),
> -            _reg: reg,
> -        };
> +        let driver = TyrPlatformDriverData { _reg: reg };
> 
>         // We need this to be dev_info!() because dev_dbg!() does not work at
>         // all in Rust for now, and we need to see whether probe succeeded.
> @@ -184,8 +184,8 @@ fn drop(self: Pin<&mut Self>) {}
> 
> #[vtable]
> impl drm::Driver for TyrDrmDriver {
> -    type Data = TyrDrmDeviceData;
> -    type RegistrationData<'a> = ();
> +    type Data = ();
> +    type RegistrationData<'bound> = TyrDrmRegistrationData<'bound>;
>     type File = TyrDrmFileData;
>     type Object = drm::gem::shmem::Object<BoData>;
>     type ParentDevice<Ctx: DeviceContext> = platform::Device<Ctx>;
> diff --git a/drivers/gpu/drm/tyr/file.rs b/drivers/gpu/drm/tyr/file.rs
> index b686041d5d6b..9f60a90d4948 100644
> --- a/drivers/gpu/drm/tyr/file.rs
> +++ b/drivers/gpu/drm/tyr/file.rs
> @@ -12,7 +12,8 @@
> 
> use crate::driver::{
>     TyrDrmDevice,
> -    TyrDrmDriver, //
> +    TyrDrmDriver,
> +    TyrDrmRegistrationData, //
> };
> 
> #[pin_data]
> @@ -31,15 +32,15 @@ fn open(_dev: &drm::Device<Self::Driver>) -> Result<Pin<KBox<Self>>> {
> 
> impl TyrDrmFileData {
>     pub(crate) fn dev_query(
> -        ddev: &TyrDrmDevice<Registered>,
> -        _reg_data: &(),
> +        _ddev: &TyrDrmDevice<Registered>,
> +        reg_data: &TyrDrmRegistrationData<'_>,
>         devquery: &mut uapi::drm_panthor_dev_query,
>         _file: &TyrDrmFile,
>     ) -> Result<u32> {
>         if devquery.pointer == 0 {
>             match devquery.type_ {
>                 uapi::drm_panthor_dev_query_type_DRM_PANTHOR_DEV_QUERY_GPU_INFO => {
> -                    devquery.size = core::mem::size_of_val(&ddev.gpu_info) as u32;
> +                    devquery.size = core::mem::size_of_val(&reg_data.gpu_info) as u32;
>                     Ok(0)
>                 }
>                 _ => Err(EINVAL),
> @@ -53,7 +54,7 @@ pub(crate) fn dev_query(
>                     )
>                     .writer();
> 
> -                    writer.write(&ddev.gpu_info)?;
> +                    writer.write(&reg_data.gpu_info)?;
> 
>                     Ok(0)
>                 }
> 
> -- 
> 2.54.0
> 


Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>