Re: [PATCH v2 3/4] gpu: nova-core: gsp: make `Cmdq` a pinned type

["Gary Guo" <gary@garyguo.net>]

On Thu Feb 26, 2026 at 2:50 PM GMT, Eliot Courtney wrote:
> Make `Cmdq` a pinned type. This is needed to use Mutex, which is needed
> to add locking to `Cmdq`.
>
> Reviewed-by: Zhi Wang <zhiw@nvidia.com>
> Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
> ---
>  drivers/gpu/nova-core/gsp.rs      | 5 +++--
>  drivers/gpu/nova-core/gsp/cmdq.rs | 9 ++++-----
>  2 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/nova-core/gsp.rs b/drivers/gpu/nova-core/gsp.rs
> index 174feaca0a6b..a6f3918c20b1 100644
> --- a/drivers/gpu/nova-core/gsp.rs
> +++ b/drivers/gpu/nova-core/gsp.rs
> @@ -112,6 +112,7 @@ pub(crate) struct Gsp {
>      /// RM log buffer.
>      logrm: LogBuffer,
>      /// Command queue.
> +    #[pin]
>      pub(crate) cmdq: Cmdq,
>      /// RM arguments.
>      rmargs: CoherentAllocation<GspArgumentsPadded>,
> @@ -132,7 +133,7 @@ pub(crate) fn new(pdev: &pci::Device<device::Bound>) -> impl PinInit<Self, Error
>                  loginit: LogBuffer::new(dev)?,
>                  logintr: LogBuffer::new(dev)?,
>                  logrm: LogBuffer::new(dev)?,
> -                cmdq: Cmdq::new(dev)?,
> +                cmdq <- Cmdq::new(dev),
>                  rmargs: CoherentAllocation::<GspArgumentsPadded>::alloc_coherent(
>                      dev,
>                      1,
> @@ -149,7 +150,7 @@ pub(crate) fn new(pdev: &pci::Device<device::Bound>) -> impl PinInit<Self, Error
>                          libos[1] = LibosMemoryRegionInitArgument::new("LOGINTR", &logintr.0)
>                      )?;
>                      dma_write!(libos[2] = LibosMemoryRegionInitArgument::new("LOGRM", &logrm.0))?;
> -                    dma_write!(rmargs[0].inner = fw::GspArgumentsCached::new(cmdq))?;
> +                    dma_write!(rmargs[0].inner = fw::GspArgumentsCached::new(&cmdq))?;

Hmm, I don't think the `&` here is needed?

Best,
Gary

>                      dma_write!(libos[3] = LibosMemoryRegionInitArgument::new("RMARGS", rmargs))?;
>                  },
>              }))
> diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
> index daf3e1d153d4..6bb1decd2af5 100644
> --- a/drivers/gpu/nova-core/gsp/cmdq.rs
> +++ b/drivers/gpu/nova-core/gsp/cmdq.rs
> @@ -474,6 +474,7 @@ pub(crate) fn command_size<M>(command: &M) -> usize
>  ///
>  /// Provides the ability to send commands and receive messages from the GSP using a shared memory
>  /// area.
> +#[pin_data]
>  pub(crate) struct Cmdq {
>      /// Device this command queue belongs to.
>      dev: ARef<device::Device>,
> @@ -501,13 +502,11 @@ impl Cmdq {
>      pub(crate) const NUM_PTES: usize = size_of::<GspMem>() >> GSP_PAGE_SHIFT;
>  
>      /// Creates a new command queue for `dev`.
> -    pub(crate) fn new(dev: &device::Device<device::Bound>) -> Result<Cmdq> {
> -        let gsp_mem = DmaGspMem::new(dev)?;
> -
> -        Ok(Cmdq {
> +    pub(crate) fn new(dev: &device::Device<device::Bound>) -> impl PinInit<Self, Error> + '_ {
> +        try_pin_init!(Self {
> +            gsp_mem: DmaGspMem::new(dev)?,
>              dev: dev.into(),
>              seq: 0,
> -            gsp_mem,
>          })
>      }
>