[PATCH v11 18/22] gpu: nova-core: Hopper/Blackwell: add FspCotVersion type

[John Hubbard]

The FSP Chain of Trust handshake is versioned, and the version the
driver must advertise depends on the GPU: Hopper speaks version 1 and
Blackwell speaks version 2. Represent that version explicitly and select
it per architecture so the boot message carries the value FSP expects.

Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
---
 drivers/gpu/nova-core/fsp.rs | 19 +++++++++++++++++++
 drivers/gpu/nova-core/gpu.rs | 16 ++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/drivers/gpu/nova-core/fsp.rs b/drivers/gpu/nova-core/fsp.rs
index cc2ebc3f6e78..5aae8282f2f0 100644
--- a/drivers/gpu/nova-core/fsp.rs
+++ b/drivers/gpu/nova-core/fsp.rs
@@ -36,6 +36,25 @@
 
 mod hal;
 
+/// FSP Chain of Trust protocol version.
+///
+/// Hopper (GH100) uses version 1, Blackwell uses version 2.
+#[derive(Debug, Clone, Copy)]
+pub(crate) struct FspCotVersion(u16);
+
+impl FspCotVersion {
+    /// Creates a new FSP CoT version.
+    pub(crate) const fn new(version: u16) -> Self {
+        Self(version)
+    }
+
+    /// Returns the raw protocol version number for the wire format.
+    #[expect(dead_code)]
+    pub(crate) const fn raw(self) -> u16 {
+        self.0
+    }
+}
+
 /// FSP message timeout in milliseconds.
 const FSP_MSG_TIMEOUT_MS: i64 = 2000;
 
diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
index 7dd736e5b190..6cdface3c618 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -21,6 +21,7 @@
         Falcon, //
     },
     fb::SysmemFlush,
+    fsp::FspCotVersion,
     gsp::{
         self,
         Gsp, //
@@ -141,6 +142,21 @@ pub(crate) const fn needs_fwsec_bootloader(self) -> bool {
     pub(crate) fn pci_config_mirror_range(self) -> Range<u32> {
         hal::gpu_hal(self).pci_config_mirror_range()
     }
+
+    /// Returns the FSP Chain of Trust (CoT) protocol version for this chipset.
+    ///
+    /// Hopper (GH100) uses version 1, Blackwell uses version 2.
+    /// Returns `None` for architectures that do not use FSP.
+    #[expect(dead_code)]
+    pub(crate) const fn fsp_cot_version(self) -> Option<FspCotVersion> {
+        match self.arch() {
+            Architecture::Hopper => Some(FspCotVersion::new(1)),
+            Architecture::BlackwellGB10x | Architecture::BlackwellGB20x => {
+                Some(FspCotVersion::new(2))
+            }
+            _ => None,
+        }
+    }
 }
 
 // TODO
-- 
2.54.0