[PATCH v4 03/10] gpu: nova-core: gsp: cmdq: group the RPC-specific part of send_single_command

[Alexandre Courbot <acourbot@nvidia.com>]

`send_single_command` handles both the transport and message layers of
the command, intertwining the logic of the two.

Reorder the code so the message layer logic is within the same
contiguous block of code, so it can easily be moved.

No functional change intended.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
---
 drivers/gpu/nova-core/gsp/cmdq.rs | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index d89f09d3f126..a27b0b41b593 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -683,18 +683,18 @@ fn send_single_command<M>(&mut self, command: M) -> Result
             .gsp_mem
             .allocate_command(size_in_bytes, Self::ALLOCATE_TIMEOUT)?;
 
-        // Extract area for the command itself. The GSP message header and the command header
-        // together are guaranteed to fit entirely into a single page, so it's ok to only look
-        // at `dst.contents.0` here.
-        let (cmd, payload_1) = M::Command::from_bytes_mut_prefix(dst.contents.0).ok_or(EIO)?;
-
-        // Fill the header and command in-place.
+        // Fill the header.
         let msg_element_init = GspMsgElement::init(self.seq, size_in_bytes);
-        let rpc_header_init = RpcMessageHeader::init(size_in_bytes, M::FUNCTION);
         // SAFETY: `dst.header` is a valid reference, and is not touched if the initializer fails.
         unsafe {
             pin_init::raw_try_init(core::ptr::from_mut(dst.header), msg_element_init)?;
         }
+
+        // Extract area for the command itself. The GSP message header and the command header
+        // together are guaranteed to fit entirely into a single page, so it's ok to only look
+        // at `dst.contents.0` here.
+        let (cmd, payload_1) = M::Command::from_bytes_mut_prefix(dst.contents.0).ok_or(EIO)?;
+        let rpc_header_init = RpcMessageHeader::init(size_in_bytes, M::FUNCTION);
         // SAFETY: `dst.header.rpc_header_mut()` is a valid reference, and is not touched if the
         // initializer fails.
         unsafe {
@@ -717,14 +717,6 @@ fn send_single_command<M>(&mut self, command: M) -> Result
         }
         drop(sbuffer);
 
-        // Compute checksum now that the whole message is ready.
-        dst.header
-            .set_checksum(Cmdq::calculate_checksum(SBufferIter::new_reader([
-                dst.header.as_bytes(),
-                dst.contents.0,
-                dst.contents.1,
-            ])));
-
         dev_dbg!(
             &self.dev,
             "GSP RPC: send: seq# {}, function={:?}, length=0x{:x}\n",
@@ -733,6 +725,14 @@ fn send_single_command<M>(&mut self, command: M) -> Result
             size_in_bytes,
         );
 
+        // Compute checksum now that the whole message is ready.
+        dst.header
+            .set_checksum(Cmdq::calculate_checksum(SBufferIter::new_reader([
+                dst.header.as_bytes(),
+                dst.contents.0,
+                dst.contents.1,
+            ])));
+
         // All set - update the write pointer and inform the GSP of the new command.
         let elem_count = dst.header.element_count();
         self.seq += 1;

-- 
2.56.0