[PATCH v3 3/5] gpu: nova-core: gsp: add reply/no-reply info to `CommandToGsp`
From: Eliot Courtney
Date: Tue Mar 03 2026 - 21:49:29 EST
Add type infrastructure to know what reply is expected from each
`CommandToGsp`. Uses a marker type `NoReply` which does not implement
`MessageFromGsp` to mark commands which don't expect a response.
Update `send_command` to wait for a reply and add `send_command_no_wait`
which sends a command that has no reply, without blocking.
This prepares for adding locking to the queue.
Tested-by: Zhi Wang <zhiw@xxxxxxxxxx>
Signed-off-by: Eliot Courtney <ecourtney@xxxxxxxxxx>
---
drivers/gpu/nova-core/gsp/boot.rs | 5 ++-
drivers/gpu/nova-core/gsp/cmdq.rs | 55 +++++++++++++++++++++++++-
drivers/gpu/nova-core/gsp/cmdq/continuation.rs | 5 ++-
drivers/gpu/nova-core/gsp/commands.rs | 16 +++-----
4 files changed, 67 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/nova-core/gsp/boot.rs b/drivers/gpu/nova-core/gsp/boot.rs
index c56029f444cb..991eb5957e3d 100644
--- a/drivers/gpu/nova-core/gsp/boot.rs
+++ b/drivers/gpu/nova-core/gsp/boot.rs
@@ -160,8 +160,9 @@ pub(crate) fn boot(
dma_write!(wpr_meta[0] = GspFwWprMeta::new(&gsp_fw, &fb_layout))?;
self.cmdq
- .send_command(bar, commands::SetSystemInfo::new(pdev))?;
- self.cmdq.send_command(bar, commands::SetRegistry::new())?;
+ .send_command_no_wait(bar, commands::SetSystemInfo::new(pdev))?;
+ self.cmdq
+ .send_command_no_wait(bar, commands::SetRegistry::new())?;
gsp_falcon.reset(bar)?;
let libos_handle = self.libos.dma_handle();
diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index 0192c85ddd75..7750f5792b21 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -51,6 +51,10 @@
sbuffer::SBufferIter, //
};
+/// Marker type representing the absence of a reply for a command. This does not implement
+/// `MessageFromGsp`.
+pub(crate) struct NoReply;
+
/// Trait implemented by types representing a command to send to the GSP.
///
/// The main purpose of this trait is to provide [`Cmdq::send_command`] with the information it
@@ -69,6 +73,10 @@ pub(crate) trait CommandToGsp {
/// Type generated by [`CommandToGsp::init`], to be written into the command queue buffer.
type Command: FromBytes + AsBytes;
+ /// Type of the reply expected from the GSP, or [`NoReply`] for commands that don't
+ /// have a reply.
+ type Reply;
+
/// Error type returned by [`CommandToGsp::init`].
type InitError;
@@ -610,7 +618,7 @@ fn send_single_command<M>(&mut self, bar: &Bar0, command: M) -> Result
/// written to by its [`CommandToGsp::init_variable_payload`] method.
///
/// Error codes returned by the command initializers are propagated as-is.
- pub(crate) fn send_command<M>(&mut self, bar: &Bar0, command: M) -> Result
+ fn send_command_internal<M>(&mut self, bar: &Bar0, command: M) -> Result
where
M: CommandToGsp,
Error: From<M::InitError>,
@@ -630,6 +638,51 @@ pub(crate) fn send_command<M>(&mut self, bar: &Bar0, command: M) -> Result
}
}
+ /// Sends `command` to the GSP and waits for the reply.
+ ///
+ /// # Errors
+ ///
+ /// - `ETIMEDOUT` if space does not become available to send the command, or if the reply is
+ /// not received within the timeout.
+ /// - `EIO` if the variable payload requested by the command has not been entirely
+ /// written to by its [`CommandToGsp::init_variable_payload`] method.
+ ///
+ /// Error codes returned by the command and reply initializers are propagated as-is.
+ pub(crate) fn send_command<M>(&mut self, bar: &Bar0, command: M) -> Result<M::Reply>
+ where
+ M: CommandToGsp,
+ M::Reply: MessageFromGsp,
+ Error: From<M::InitError>,
+ Error: From<<M::Reply as MessageFromGsp>::InitError>,
+ {
+ self.send_command_internal(bar, command)?;
+
+ loop {
+ match self.receive_msg::<M::Reply>(Self::RECEIVE_TIMEOUT) {
+ Ok(reply) => break Ok(reply),
+ Err(ERANGE) => continue,
+ Err(e) => break Err(e),
+ }
+ }
+ }
+
+ /// Sends `command` to the GSP without waiting for a reply.
+ ///
+ /// # Errors
+ ///
+ /// - `ETIMEDOUT` if space does not become available within the timeout.
+ /// - `EIO` if the variable payload requested by the command has not been entirely
+ /// written to by its [`CommandToGsp::init_variable_payload`] method.
+ ///
+ /// Error codes returned by the command initializers are propagated as-is.
+ pub(crate) fn send_command_no_wait<M>(&mut self, bar: &Bar0, command: M) -> Result
+ where
+ M: CommandToGsp<Reply = NoReply>,
+ Error: From<M::InitError>,
+ {
+ self.send_command_internal(bar, command)
+ }
+
/// Wait for a message to become available on the message queue.
///
/// This works purely at the transport layer and does not interpret or validate the message
diff --git a/drivers/gpu/nova-core/gsp/cmdq/continuation.rs b/drivers/gpu/nova-core/gsp/cmdq/continuation.rs
index 637942917237..8a6bb8fa7e60 100644
--- a/drivers/gpu/nova-core/gsp/cmdq/continuation.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq/continuation.rs
@@ -6,7 +6,7 @@
use kernel::prelude::*;
-use super::CommandToGsp;
+use super::{CommandToGsp, NoReply};
use crate::{
gsp::fw::{
@@ -63,6 +63,7 @@ fn new(data: &'a [u8]) -> Self {
impl<'a> CommandToGsp for ContinuationRecord<'a> {
const FUNCTION: MsgFunction = MsgFunction::ContinuationRecord;
type Command = ();
+ type Reply = NoReply;
type InitError = Infallible;
fn init(&self) -> impl Init<Self::Command, Self::InitError> {
@@ -144,6 +145,7 @@ fn new(command: C, payload: KVVec<u8>) -> Self {
impl<C: CommandToGsp> CommandToGsp for SplitCommand<C> {
const FUNCTION: MsgFunction = C::FUNCTION;
type Command = C::Command;
+ type Reply = C::Reply;
type InitError = C::InitError;
fn init(&self) -> impl Init<Self::Command, Self::InitError> {
@@ -206,6 +208,7 @@ fn new(len: usize) -> Result<Self> {
impl CommandToGsp for TestPayload {
const FUNCTION: MsgFunction = MsgFunction::Nop;
type Command = TestHeader;
+ type Reply = NoReply;
type InitError = Infallible;
fn init(&self) -> impl Init<Self::Command, Self::InitError> {
diff --git a/drivers/gpu/nova-core/gsp/commands.rs b/drivers/gpu/nova-core/gsp/commands.rs
index 88df117ba575..77054c92fcc2 100644
--- a/drivers/gpu/nova-core/gsp/commands.rs
+++ b/drivers/gpu/nova-core/gsp/commands.rs
@@ -23,7 +23,8 @@
cmdq::{
Cmdq,
CommandToGsp,
- MessageFromGsp, //
+ MessageFromGsp,
+ NoReply, //
},
fw::{
commands::*,
@@ -48,6 +49,7 @@ pub(crate) fn new(pdev: &'a pci::Device<device::Bound>) -> Self {
impl<'a> CommandToGsp for SetSystemInfo<'a> {
const FUNCTION: MsgFunction = MsgFunction::GspSetSystemInfo;
type Command = GspSetSystemInfo;
+ type Reply = NoReply;
type InitError = Error;
fn init(&self) -> impl Init<Self::Command, Self::InitError> {
@@ -99,6 +101,7 @@ pub(crate) fn new() -> Self {
impl CommandToGsp for SetRegistry {
const FUNCTION: MsgFunction = MsgFunction::SetRegistry;
type Command = PackedRegistryTable;
+ type Reply = NoReply;
type InitError = Infallible;
fn init(&self) -> impl Init<Self::Command, Self::InitError> {
@@ -178,6 +181,7 @@ pub(crate) fn wait_gsp_init_done(cmdq: &mut Cmdq) -> Result {
impl CommandToGsp for GetGspStaticInfo {
const FUNCTION: MsgFunction = MsgFunction::GetGspStaticInfo;
type Command = GspStaticConfigInfo;
+ type Reply = GetGspStaticInfoReply;
type InitError = Infallible;
fn init(&self) -> impl Init<Self::Command, Self::InitError> {
@@ -231,13 +235,5 @@ pub(crate) fn gpu_name(&self) -> core::result::Result<&str, GpuNameError> {
/// Send the [`GetGspInfo`] command and awaits for its reply.
pub(crate) fn get_gsp_info(cmdq: &mut Cmdq, bar: &Bar0) -> Result<GetGspStaticInfoReply> {
- cmdq.send_command(bar, GetGspStaticInfo)?;
-
- loop {
- match cmdq.receive_msg::<GetGspStaticInfoReply>(Cmdq::RECEIVE_TIMEOUT) {
- Ok(info) => return Ok(info),
- Err(ERANGE) => continue,
- Err(e) => return Err(e),
- }
- }
+ cmdq.send_command(bar, GetGspStaticInfo)
}
--
2.53.0