[PATCH v4 12/13] gpu: nova-core: gsp: Wait for gsp initialization to complete

[Joel Fernandes <joelagnelf@nvidia.com>]

From: Alistair Popple <apopple@nvidia.com>

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.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Co-developed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
---
 drivers/gpu/nova-core/gsp/boot.rs     |  2 ++
 drivers/gpu/nova-core/gsp/commands.rs | 48 +++++++++++++++++++++++++--
 2 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/boot.rs b/drivers/gpu/nova-core/gsp/boot.rs
index e9be10374c51..c0afafbf35f6 100644
--- a/drivers/gpu/nova-core/gsp/boot.rs
+++ b/drivers/gpu/nova-core/gsp/boot.rs
@@ -236,6 +236,8 @@ pub(crate) fn boot(
         };
         GspSequencer::run(&mut self.cmdq, seq_params, Delta::from_secs(10))?;
 
+        commands::gsp_init_done(&mut self.cmdq, Delta::from_secs(10))?;
+
         Ok(())
     }
 }
diff --git a/drivers/gpu/nova-core/gsp/commands.rs b/drivers/gpu/nova-core/gsp/commands.rs
index d5be3bf10684..07abfb54f9d7 100644
--- a/drivers/gpu/nova-core/gsp/commands.rs
+++ b/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, //
@@ -20,6 +31,37 @@
     sbuffer::SBufferIter,
 };
 
+/// 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 gsp_init_done(cmdq: &mut Cmdq, timeout: Delta) -> Result {
+    loop {
+        match cmdq.receive_msg::<GspInitDone>(timeout) {
+            Ok(_) => break Ok(()),
+            Err(ERANGE) => continue,
+            Err(e) => break Err(e),
+        }
+    }
+}
+
 /// The `GspSetSystemInfo` command.
 pub(crate) struct SetSystemInfo<'a> {
     pdev: &'a pci::Device<device::Bound>,
-- 
2.34.1