Re: [PATCH 7/9] gpu: nova-core: gsp: add RM control command infrastructure

[Danilo Krummrich]

On Fri Feb 27, 2026 at 1:32 PM CET, Eliot Courtney wrote:
> +/// Command for sending an RM control message to the GSP.
> +struct RmControl<'a> {
> +    h_client: u32,
> +    h_object: u32,
> +    cmd: RmControlMsgFunction,
> +    params: &'a [u8],
> +}

Please expand the documentation, especially the fields.

> +impl<'a> RmControl<'a> {
> +    /// Creates a new RM control command.
> +    fn new(h_client: u32, h_object: u32, cmd: RmControlMsgFunction, params: &'a [u8]) -> Self {
> +        Self {
> +            h_client,
> +            h_object,
> +            cmd,
> +            params,
> +        }
> +    }
> +}
> +
> +impl CommandToGsp for RmControl<'_> {
> +    const FUNCTION: MsgFunction = MsgFunction::GspRmControl;
> +    type Command = GspRmControl;
> +    type Reply = RmControlReply;
> +    type InitError = Infallible;
> +
> +    fn init(&self) -> impl Init<Self::Command, Self::InitError> {
> +        GspRmControl::new(
> +            self.h_client,
> +            self.h_object,
> +            self.cmd,
> +            self.params.len() as u32,
> +        )
> +    }
> +
> +    fn variable_payload_len(&self) -> usize {
> +        self.params.len()
> +    }
> +
> +    fn init_variable_payload(
> +        &self,
> +        dst: &mut SBufferIter<array::IntoIter<&mut [u8], 2>>,
> +    ) -> Result {
> +        dst.write_all(self.params)
> +    }
> +}
> +
> +/// Response from an RM control message.
> +pub(crate) struct RmControlReply {
> +    status: NvStatus,
> +    params: KVVec<u8>,
> +}
> +
> +impl MessageFromGsp for RmControlReply {
> +    const FUNCTION: MsgFunction = MsgFunction::GspRmControl;
> +    type Message = GspRmControl;
> +    type InitError = Error;
> +
> +    fn read(
> +        msg: &Self::Message,
> +        sbuffer: &mut SBufferIter<array::IntoIter<&[u8], 2>>,
> +    ) -> Result<Self, Self::InitError> {
> +        Ok(RmControlReply {
> +            status: msg.status(),
> +            params: sbuffer.flush_into_kvvec(GFP_KERNEL)?,
> +        })
> +    }
> +}
> +
> +/// Sends an RM control command, checks the reply status, and returns the raw parameter bytes.
> +#[expect(dead_code)]
> +fn send_rm_control(

Why isn't this a method of Cmdq?

> +    cmdq: &Cmdq,
> +    bar: &Bar0,
> +    h_client: u32,
> +    h_object: u32,
> +    cmd: RmControlMsgFunction,
> +    params: &[u8],
> +) -> Result<KVVec<u8>> {
> +    let reply = cmdq.send_sync_command(bar, RmControl::new(h_client, h_object, cmd, params))?;

Why not let the caller construct RmControl?

> +
> +    Result::from(reply.status)?;
> +
> +    Ok(reply.params)
> +}
>
> -- 
> 2.53.0