[PATCH v2 12/12] 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.

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     |  8 +++++-
 drivers/gpu/nova-core/gsp/commands.rs | 39 +++++++++++++++++++++++++--
 2 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/boot.rs b/drivers/gpu/nova-core/gsp/boot.rs
index 761020a11153..0dd8099f5f8c 100644
--- a/drivers/gpu/nova-core/gsp/boot.rs
+++ b/drivers/gpu/nova-core/gsp/boot.rs
@@ -18,7 +18,11 @@
     FIRMWARE_VERSION,
 };
 use crate::gpu::Chipset;
-use crate::gsp::commands::{build_registry, set_system_info};
+use crate::gsp::commands::{
+    build_registry,
+    gsp_init_done,
+    set_system_info, //
+};
 use crate::gsp::{
     sequencer::{
         GspSequencer,
@@ -221,6 +225,8 @@ pub(crate) fn boot(
         };
         GspSequencer::run(&mut self.cmdq, seq_params, Delta::from_secs(10))?;
 
+        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 338d1695027f..475c6d9410c5 100644
--- a/drivers/gpu/nova-core/gsp/commands.rs
+++ b/drivers/gpu/nova-core/gsp/commands.rs
@@ -4,16 +4,51 @@
 use kernel::device;
 use kernel::pci;
 use kernel::prelude::*;
-use kernel::transmute::AsBytes;
+use kernel::time::Delta;
+use kernel::transmute::{
+    AsBytes,
+    FromBytes, //
+};
 
 use super::fw::commands::*;
 use super::fw::MsgFunction;
 use crate::driver::Bar0;
 use crate::gsp::cmdq::Cmdq;
-use crate::gsp::cmdq::{CommandToGsp, CommandToGspBase, CommandToGspWithPayload};
+use crate::gsp::cmdq::{
+    CommandToGsp,
+    CommandToGspBase,
+    CommandToGspWithPayload,
+    MessageFromGsp, //
+};
 use crate::gsp::GSP_PAGE_SIZE;
 use crate::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 AsBytes for 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;
+}
+
+/// Waits for GSP initialization to complete.
+pub(crate) fn gsp_init_done(cmdq: &mut Cmdq, timeout: Delta) -> Result {
+    loop {
+        match cmdq.receive_msg_from_gsp::<GspInitDone, ()>(timeout, |_, _| Ok(())) {
+            Ok(_) => break Ok(()),
+            Err(ERANGE) => continue,
+            Err(e) => break Err(e),
+        }
+    }
+}
+
 // For now we hard-code the registry entries. Future work will allow others to
 // be added as module parameters.
 const GSP_REGISTRY_NUM_ENTRIES: usize = 3;
-- 
2.34.1