gpu: nova-core: gsp: Wait for gsp initialization to complete

This adds the GSP init done command to wait for GSP initialization
to complete. Once this command has been received the GSP is fully
operational and will respond properly to normal RPC commands.

Signed-off-by: Alistair Popple <apopple@nvidia.com>
Co-developed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
[acourbot@nvidia.com: move new definitions to end of commands.rs, rename
to `wait_gsp_init_done` and remove timeout argument.]
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251114195552.739371-13-joelagnelf@nvidia.com>

drivers/gpu/nova-core/gsp/boot.rs

@@ -236,6 +236,9 @@ pub(crate) fn boot(
         };
         GspSequencer::run(&mut self.cmdq, seq_params)?;
 
+        // Wait until GSP is fully initialized.
+        commands::wait_gsp_init_done(&mut self.cmdq)?;
+
         Ok(())
     }
 }

drivers/gpu/nova-core/gsp/commands.rs

@@ -1,17 +1,28 @@
 // SPDX-License-Identifier: GPL-2.0
 
-use core::convert::Infallible;
+use core::{
+    array,
+    convert::Infallible, //
+};
 
 use kernel::{
     device,
     pci,
     prelude::*,
-    transmute::AsBytes, //
+    time::Delta,
+    transmute::{
+        AsBytes,
+        FromBytes, //
+    }, //
 };
 
 use crate::{
     gsp::{
-        cmdq::CommandToGsp,
+        cmdq::{
+            Cmdq,
+            CommandToGsp,
+            MessageFromGsp, //
+        },
         fw::{
             commands::*,
             MsgFunction, //
@@ -127,3 +138,34 @@ fn init_variable_payload(
         dst.write_all(string_data.as_slice())
     }
 }
+
+/// Message type for GSP initialization done notification.
+struct GspInitDone {}
+
+// SAFETY: `GspInitDone` is a zero-sized type with no bytes, therefore it
+// trivially has no uninitialized bytes.
+unsafe impl FromBytes for GspInitDone {}
+
+impl MessageFromGsp for GspInitDone {
+    const FUNCTION: MsgFunction = MsgFunction::GspInitDone;
+    type InitError = Infallible;
+    type Message = GspInitDone;
+
+    fn read(
+        _msg: &Self::Message,
+        _sbuffer: &mut SBufferIter<array::IntoIter<&[u8], 2>>,
+    ) -> Result<Self, Self::InitError> {
+        Ok(GspInitDone {})
+    }
+}
+
+/// Waits for GSP initialization to complete.
+pub(crate) fn wait_gsp_init_done(cmdq: &mut Cmdq) -> Result {
+    loop {
+        match cmdq.receive_msg::<GspInitDone>(Delta::from_secs(10)) {
+            Ok(_) => break Ok(()),
+            Err(ERANGE) => continue,
+            Err(e) => break Err(e),
+        }
+    }
+}