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

[Zhi Wang <zhiw@nvidia.com>]

On Fri, 27 Feb 2026 21:32:12 +0900
Eliot Courtney <ecourtney@nvidia.com> wrote:

Tested-by: Zhi Wang <zhiw@nvidia.com>

> Add `RmControl` which implements CommandToGsp for sending RM control
> RPCs.
> 
> Add `RmControlReply` which implements MessageFromGsp for getting the
> reply back.
> 
> Add `send_rm_control` which sends an RM control RPC via the command
> queue using the above structures.
> 
> This gives a generic way to send each RM control RPC. Each new RM
> control RPC can be added by extending RmControlMsgFunction and adding
> its bindings wrappers and writing a helper function to send it via
> `send_rm_control`.
> 
> Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
> ---
>  drivers/gpu/nova-core/gsp.rs             |   1 +
>  drivers/gpu/nova-core/gsp/rm.rs          |   3 +
>  drivers/gpu/nova-core/gsp/rm/commands.rs | 111
> +++++++++++++++++++++++++++++++ 3 files changed, 115 insertions(+)
> 
> diff --git a/drivers/gpu/nova-core/gsp.rs
> b/drivers/gpu/nova-core/gsp.rs index a6f3918c20b1..1a1c4e9808ac 100644
> --- a/drivers/gpu/nova-core/gsp.rs
> +++ b/drivers/gpu/nova-core/gsp.rs
> @@ -17,6 +17,7 @@
>  pub(crate) mod cmdq;
>  pub(crate) mod commands;
>  mod fw;
> +pub(crate) mod rm;
>  mod sequencer;
>  
>  pub(crate) use fw::{
> diff --git a/drivers/gpu/nova-core/gsp/rm.rs
> b/drivers/gpu/nova-core/gsp/rm.rs new file mode 100644
> index 000000000000..10e879a3e842
> --- /dev/null
> +++ b/drivers/gpu/nova-core/gsp/rm.rs
> @@ -0,0 +1,3 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +pub(crate) mod commands;
> diff --git a/drivers/gpu/nova-core/gsp/rm/commands.rs
> b/drivers/gpu/nova-core/gsp/rm/commands.rs new file mode 100644
> index 000000000000..16bcf88644db
> --- /dev/null
> +++ b/drivers/gpu/nova-core/gsp/rm/commands.rs
> @@ -0,0 +1,111 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +use core::{
> +    array,
> +    convert::Infallible, //
> +};
> +
> +use kernel::prelude::*;
> +
> +use crate::{
> +    driver::Bar0,
> +    gsp::{
> +        cmdq::{
> +            Cmdq,
> +            CommandToGsp,
> +            MessageFromGsp, //
> +        },
> +        fw::{
> +            rm::*,
> +            MsgFunction,
> +            NvStatus, //
> +        },
> +    },
> +    sbuffer::SBufferIter,
> +};
> +
> +/// Command for sending an RM control message to the GSP.
> +struct RmControl<'a> {
> +    h_client: u32,
> +    h_object: u32,
> +    cmd: RmControlMsgFunction,
> +    params: &'a [u8],
> +}
> +
> +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(
> +    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))?; +
> +    Result::from(reply.status)?;
> +
> +    Ok(reply.params)
> +}
>