Re: [PATCH 08/11] gpu: nova-core: Add basic Turing HAL

[Joel Fernandes <joelagnelf@nvidia.com>]

On Fri, Nov 14, 2025 at 05:30:41PM -0600, Timur Tabi wrote:
> Add the basic HAL for recognizing Turing GPUs.  This isn't enough
> to support booting GSP-RM on Turing, but it's a start.
> 
> Note that GA100, which boots using the same method as Turing, is not
> supported yet.
> 
> Signed-off-by: Timur Tabi <ttabi@nvidia.com>
> ---
>  drivers/gpu/nova-core/falcon/hal.rs       |  6 +-
>  drivers/gpu/nova-core/falcon/hal/tu102.rs | 73 +++++++++++++++++++++++
>  2 files changed, 78 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/nova-core/falcon/hal/tu102.rs
> 
> diff --git a/drivers/gpu/nova-core/falcon/hal.rs b/drivers/gpu/nova-core/falcon/hal.rs
> index c77a1568ea96..7a6610e9d0a8 100644
> --- a/drivers/gpu/nova-core/falcon/hal.rs
> +++ b/drivers/gpu/nova-core/falcon/hal.rs
> @@ -13,6 +13,7 @@
>  };
>  
>  mod ga102;
> +mod tu102;
>  
>  /// Hardware Abstraction Layer for Falcon cores.
>  ///
> @@ -60,9 +61,12 @@ pub(super) fn falcon_hal<E: FalconEngine + 'static>(
>      use Chipset::*;
>  
>      let hal = match chipset {
> +        TU102 | TU104 | TU106 | TU116 | TU117 => {
> +            KBox::new(tu102::Tu102::<E>::new(), GFP_KERNEL)? as KBox<dyn FalconHal<E>>
> +        },
>          GA102 | GA103 | GA104 | GA106 | GA107 | AD102 | AD103 | AD104 | AD106 | AD107 => {
>              KBox::new(ga102::Ga102::<E>::new(), GFP_KERNEL)? as KBox<dyn FalconHal<E>>
> -        }
> +        },
>          _ => return Err(ENOTSUPP),
>      };
>  
> diff --git a/drivers/gpu/nova-core/falcon/hal/tu102.rs b/drivers/gpu/nova-core/falcon/hal/tu102.rs
> new file mode 100644
> index 000000000000..edb8447d7263
> --- /dev/null
> +++ b/drivers/gpu/nova-core/falcon/hal/tu102.rs
> @@ -0,0 +1,73 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +use core::marker::PhantomData;
> +
> +use kernel::io::poll::read_poll_timeout;
> +use kernel::prelude::*;
> +use kernel::time::Delta;
> +
> +use crate::driver::Bar0;
> +use crate::falcon::{
> +    Falcon, FalconBromParams, FalconEngine
> +};
> +use crate::regs;
> +
> +use super::FalconHal;
> +
> +pub(super) struct Tu102<E: FalconEngine>(PhantomData<E>);
> +
> +impl<E: FalconEngine> Tu102<E> {
> +    pub(super) fn new() -> Self {
> +        Self(PhantomData)
> +    }
> +}
> +
> +impl<E: FalconEngine> FalconHal<E> for Tu102<E> {
> +    fn select_core(&self, _falcon: &Falcon<E>, _bar: &Bar0) -> Result {
> +        Ok(())
> +    }
> +
> +    fn signature_reg_fuse_version(
> +        &self,
> +        _falcon: &Falcon<E>,
> +        _bar: &Bar0,
> +        _engine_id_mask: u16,
> +        _ucode_id: u8,
> +    ) -> Result<u32> {
> +        Ok(0)
> +    }
> +
> +    fn program_brom(&self, _falcon: &Falcon<E>, _bar: &Bar0, _params: &FalconBromParams) -> Result {
> +        Ok(())
> +    }
> +
> +    fn is_riscv_active(&self, bar: &Bar0) -> bool {
> +        let cpuctl = regs::NV_PRISCV_RISCV_CORE_SWITCH_RISCV_STATUS::read(bar, &E::ID);
> +        cpuctl.active_stat()
> +    }
> +
> +    fn reset_wait_mem_scrubbing(&self, bar: &Bar0) -> Result {
> +        read_poll_timeout(
> +            || Ok(regs::NV_PFALCON_FALCON_DMACTL::read(bar, &E::ID)),
> +            |r| r.mem_scrubbing_done(),
> +            Delta::ZERO,
> +            Delta::from_millis(10),
> +        )
> +        .map(|_| ())
> +    }
> +
> +    fn reset_eng(&self, bar: &Bar0) -> Result {
> +        regs::NV_PFALCON_FALCON_ENGINE::update(bar, &E::ID, |v| v.set_reset(true));
> +
> +        // TODO[DLAY]: replace with udelay() or equivalent once available.
> +        // TIMEOUT: falcon engine should not take more than 10us to reset.
> +        let _: Result =
> +            read_poll_timeout(|| Ok(()), |_| false, Delta::ZERO, Delta::from_micros(10));

You need to run with CLIPPY=1. I am getting several clippy errors with the patchset:

error: matching over `()` is more explicit
  --> drivers/gpu/nova-core/falcon/hal/tu102.rs:63:43
   |
63 |             read_poll_timeout(|| Ok(()), |_| false, Delta::ZERO, Delta::from_micros(10));
   |                                           ^ help: use `()` instead of `_`: `()`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ignored_unit_patterns
   = note: `-D clippy::ignored-unit-patterns` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::ignored_unit_patterns)]`

thanks,

 - Joel