[PATCH 21/27] gpu: nova-core: gsp: add the GMC boot event dispatcher

[John Hubbard]

The r000 GSP boot protocol sends its two load-and-execute events as GMC
commands, each identified by a command id.

Nova-core has a handler for each of the two events, but nothing that
reads a command id and selects between them.

Add the dispatcher, keyed on the two command ids from the r000 bindings.

Assisted-by: Cursor:claude-opus-5
Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
---
 drivers/gpu/nova-core/gsp/boot.rs | 62 +++++++++++++++++++++++++++++--
 drivers/gpu/nova-core/gsp/fw.rs   | 10 +++++
 2 files changed, 69 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/boot.rs b/drivers/gpu/nova-core/gsp/boot.rs
index d62a5c834ccf..15933ecc061b 100644
--- a/drivers/gpu/nova-core/gsp/boot.rs
+++ b/drivers/gpu/nova-core/gsp/boot.rs
@@ -36,7 +36,11 @@
     },
     gsp::{
         cmdq::Cmdq,
-        commands, //
+        commands,
+        fw::{
+            GMCAPI_CMD_EXEC_GENERIC_BOOTLOADER,
+            GMCAPI_CMD_EXEC_HS_BINARY, //
+        }, //
     },
     regs, //
 };
@@ -162,6 +166,60 @@ fn core_resume(
         Ok(())
     }
 
+    /// Dispatch one GMC boot event to its load-and-execute handler.
+    ///
+    /// LIBOS2 chipsets send `GMCAPI_CMD_EXEC_GENERIC_BOOTLOADER` and LIBOS3 chipsets send
+    /// `GMCAPI_CMD_EXEC_HS_BINARY`, so a given GPU only ever reaches one of the two handlers.
+    ///
+    /// # Errors
+    ///
+    /// - `EINVAL` if `command_id` is not a load-and-execute command.
+    ///
+    /// Errors from the handlers are propagated as-is.
+    #[expect(dead_code)]
+    #[allow(clippy::too_many_arguments)]
+    fn dispatch_gmc_boot_event(
+        command_id: u32,
+        payload: &[u8],
+        bootloader: &GenericBootloader,
+        gsp_falcon: &Falcon<'_, Gsp>,
+        sec2_falcon: &Falcon<'_, Sec2>,
+        bar: Bar0<'_>,
+        dev: &device::Device,
+        bootloader_app_version: u32,
+        libos_dma_handle: u64,
+    ) -> Result {
+        match command_id {
+            GMCAPI_CMD_EXEC_GENERIC_BOOTLOADER => Self::handle_load_exec_bootloader(
+                payload,
+                bootloader,
+                gsp_falcon,
+                sec2_falcon,
+                bar,
+                dev,
+                bootloader_app_version,
+                libos_dma_handle,
+            ),
+            GMCAPI_CMD_EXEC_HS_BINARY => Self::handle_load_exec_hs_binary(
+                payload,
+                gsp_falcon,
+                sec2_falcon,
+                bar,
+                dev,
+                bootloader_app_version,
+                libos_dma_handle,
+            ),
+            _ => {
+                dev_err!(
+                    dev,
+                    "Unexpected GMC boot event: command_id={:#010x}\n",
+                    command_id
+                );
+                Err(EINVAL)
+            }
+        }
+    }
+
     /// Handle a `GSP_LOAD_EXEC_GENERIC_BOOTLOADER` event.
     ///
     /// The driver does not copy the image the GSP asks for. It writes the descriptor the event
@@ -175,7 +233,6 @@ fn core_resume(
     ///   size this driver mirrors, or the event names a context DMA slot or an aperture that does
     ///   not exist.
     /// - `ETIMEDOUT` if the GSP does not suspend, or the image does not halt, in time.
-    #[expect(dead_code)]
     #[allow(clippy::too_many_arguments)]
     fn handle_load_exec_bootloader(
         payload: &[u8],
@@ -268,7 +325,6 @@ fn handle_load_exec_bootloader(
     /// - `EINVAL` if the payload is shorter than the parameter block, or the ucode id does not
     ///   fit the BROM register field.
     /// - `ETIMEDOUT` if the GSP does not suspend, or the binary does not halt, in time.
-    #[expect(dead_code)]
     #[allow(clippy::too_many_arguments)]
     fn handle_load_exec_hs_binary(
         payload: &[u8],
diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index 83f7d2042aa1..4772af362117 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -979,6 +979,16 @@ pub(crate) struct GmcApiHeader {
 /// `GMCAPI_HEADER_COMMAND_ID_MASK`. The remaining byte carries flags.
 const GMCAPI_COMMAND_ID_MASK: u32 = 0x00ff_ffff;
 
+/// GMC command asking the driver to run the generic falcon bootloader against a descriptor the
+/// GSP supplies.
+pub(crate) const GMCAPI_CMD_EXEC_GENERIC_BOOTLOADER: u32 =
+    r000_00::GMCAPI_COMMANDS_GMCAPI_CMD_EXEC_GENERIC_BOOTLOADER;
+
+/// GMC command asking the driver to run a high-security binary the GSP has placed in the
+/// framebuffer.
+pub(crate) const GMCAPI_CMD_EXEC_HS_BINARY: u32 =
+    r000_00::GMCAPI_COMMANDS_GMCAPI_CMD_EXEC_HS_BINARY;
+
 static_assert!(size_of::<GmcApiHeader>() == 40);
 
 impl GmcApiHeader {
-- 
2.55.0