[PATCH v2 30/31] gpu: nova-core: print GMC command names in debug logs

Each GMC command has a name and a numeric ID.

Nova-core has been printing a bare numeric ID for GMC send and receive
debug lines. For example, 0x10001 instead of GSP_INIT.

Add Display formatting and decoding, so that we print the command name,
in addition to the ID. Example output:

nova-core 0000:c2:00.0: GSP GMC: send: seq# 0, command=GSP_INIT (0x10001), length=0xf8
nova-core 0000:c2:00.0: GSP GMC: event: seq# 0, command=GSP_INIT (0x10001), length=0x550

Assisted-by: Cursor:grok-4.6
Signed-off-by: John Hubbard <[email protected]>
---
 drivers/gpu/nova-core/gsp/boot.rs |  5 ++-
 drivers/gpu/nova-core/gsp/cmdq.rs |  9 +++--
 drivers/gpu/nova-core/gsp/fw.rs   | 67 +++++++++++++++++++++++++++++++
 3 files changed, 75 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/boot.rs b/drivers/gpu/nova-core/gsp/boot.rs
index e66e8e454e27..51c5b2522408 100644
--- a/drivers/gpu/nova-core/gsp/boot.rs
+++ b/drivers/gpu/nova-core/gsp/boot.rs
@@ -45,6 +45,7 @@
         commands,
         fw::{
             BindataArgs,
+            GmcCommand,
             GspArgumentsPadded,
             GMCAPI_CMD_EXEC_GENERIC_BOOTLOADER,
             GMCAPI_CMD_EXEC_HS_BINARY, //
@@ -278,8 +279,8 @@ fn dispatch_gmc_boot_event(
             _ => {
                 dev_err!(
                     dev,
-                    "Unexpected GMC boot event: command_id={:#010x}\n",
-                    command_id
+                    "Unexpected GMC boot event: command={}\n",
+                    GmcCommand(command_id)
                 );
                 Err(EINVAL)
             }
diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index fb7f000a5a7d..8e97cc71f2b6 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -52,6 +52,7 @@
     driver::Bar0,
     gsp::{
         fw::{
+            GmcCommand,
             GspGmcMsgElement,
             GspMsgElement,
             MsgFunction,
@@ -898,9 +899,9 @@ fn send_gmc(
 
         dev_dbg!(
             &self.dev,
-            "GSP GMC: send: seq# {}, command_id=0x{:x}, length=0x{:x}\n",
+            "GSP GMC: send: seq# {}, command={}, length=0x{:x}\n",
             rpc_seq,
-            command_id,
+            GmcCommand(command_id),
             dst.header.length(),
         );
 
@@ -1301,9 +1302,9 @@ fn receive_gmc_and_dispatch<R>(
 
             dev_dbg!(
                 &self.dev,
-                "GSP GMC: event: seq# {}, command_id=0x{:x}, length=0x{:x}\n",
+                "GSP GMC: event: seq# {}, command={}, length=0x{:x}\n",
                 header.gmc.sequence,
-                command_id,
+                GmcCommand(command_id),
                 length,
             );
 
diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index 4f34c246cb3f..927332203a43 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -12,6 +12,7 @@
 use kernel::{
     bitfield,
     dma::Coherent,
+    fmt,
     io::io_write,
     prelude::*,
     ptr::{
@@ -722,6 +723,72 @@ unsafe impl AsBytes for GmcApiHeader {}
 // SAFETY: All fields are integer types for which all bit patterns are valid.
 unsafe impl FromBytes for GmcApiHeader {}
 
+/// [`fmt::Display`] writes the command name and the numeric id, for example
+/// `GSP_INIT (0x10001)`. An unrecognized id writes `UNKNOWN` and the same numeric form.
+#[derive(Copy, Clone)]
+pub(crate) struct GmcCommand(pub(crate) u32);
+
+impl GmcCommand {
+    fn name(self) -> &'static str {
+        match self.0 {
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_GSP_INIT => "GSP_INIT",
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_EXEC_GENERIC_BOOTLOADER => {
+                "EXEC_GENERIC_BOOTLOADER"
+            }
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_EXEC_HS_BINARY => "EXEC_HS_BINARY",
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_GSP_SUSPEND => "GSP_SUSPEND",
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_GSP_RESUME_DONE => "GSP_RESUME_DONE",
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_ADD_VGPU_TYPE => "ADD_VGPU_TYPE",
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_QUERY_SUPPORTED_VGPU_TYPES => {
+                "QUERY_SUPPORTED_VGPU_TYPES"
+            }
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_QUERY_CREATABLE_VGPU_TYPES => {
+                "QUERY_CREATABLE_VGPU_TYPES"
+            }
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_ASSIGN_VGPU_TYPE => "ASSIGN_VGPU_TYPE",
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_DEASSIGN_VGPU_TYPE => "DEASSIGN_VGPU_TYPE",
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_QUERY_VGPU_PROPERTIES => "QUERY_VGPU_PROPERTIES",
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_QUERY_ASSIGNED_VF_VGPU_TYPE => {
+                "QUERY_ASSIGNED_VF_VGPU_TYPE"
+            }
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_BOOTLOAD_GSP_VGPU_PLUGIN_TASK => {
+                "BOOTLOAD_GSP_VGPU_PLUGIN_TASK"
+            }
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_SHUTDOWN_GSP_VGPU_PLUGIN_TASK => {
+                "SHUTDOWN_GSP_VGPU_PLUGIN_TASK"
+            }
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_SHUTDOWN_GSP_VGPU_PLUGIN_TASK_COMPLETE => {
+                "SHUTDOWN_GSP_VGPU_PLUGIN_TASK_COMPLETE"
+            }
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_CLEANUP_GSP_VGPU_PLUGIN_RESOURCES => {
+                "CLEANUP_GSP_VGPU_PLUGIN_RESOURCES"
+            }
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_VGPU_PLUGIN_TRIGGERED_EVENT => {
+                "VGPU_PLUGIN_TRIGGERED_EVENT"
+            }
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_VGPU_MGR_SCRUB_GUEST_FB => {
+                "VGPU_MGR_SCRUB_GUEST_FB"
+            }
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_VGPU_MGR_ALLOC_GSP_CEUTILS => {
+                "VGPU_MGR_ALLOC_GSP_CEUTILS"
+            }
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_VGPU_MGR_FREE_GSP_CEUTILS => {
+                "VGPU_MGR_FREE_GSP_CEUTILS"
+            }
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_SCHED_CONTROL => "SCHED_CONTROL",
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_MMU_FAULT_QUEUED => "MMU_FAULT_QUEUED",
+            bindings::GMCAPI_COMMANDS_GMCAPI_CMD_INVALID => "INVALID",
+            _ => "UNKNOWN",
+        }
+    }
+}
+
+impl fmt::Display for GmcCommand {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{} (0x{:x})", self.name(), self.0)
+    }
+}
+
 /// Header for an unencrypted GMC API message in the GSP command queue.
 ///
 /// The fields before `gmc` match `GSP_MSG_QUEUE_ELEMENT` through its
-- 
2.55.0