[PATCH v6 23/34] gpu: nova-core: Hopper/Blackwell: add FSP message structures

[John Hubbard <jhubbard@nvidia.com>]

Add the NVDM COT payload, FSP message, and FSP response structures
needed for FSP Chain of Trust communication. Also add FmcSignatures
to hold the hash, public key, and signature extracted from FMC firmware.

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 drivers/gpu/nova-core/firmware.rs |  5 +-
 drivers/gpu/nova-core/fsp.rs      | 78 +++++++++++++++++++++++++++++++
 2 files changed, 82 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/nova-core/firmware.rs b/drivers/gpu/nova-core/firmware.rs
index 6a0a02177f6f..be41e07b8448 100644
--- a/drivers/gpu/nova-core/firmware.rs
+++ b/drivers/gpu/nova-core/firmware.rs
@@ -26,6 +26,9 @@
     },
 };
 
+#[expect(unused)]
+pub(crate) use elf::elf_section;
+
 pub(crate) mod booter;
 pub(crate) mod fsp;
 pub(crate) mod fwsec;
@@ -627,7 +630,7 @@ fn elf32_section<'a>(elf: &'a [u8], name: &str) -> Option<&'a [u8]> {
     }
 
     /// Automatically detects ELF32 vs ELF64 based on the ELF header.
-    pub(super) fn elf_section<'a>(elf: &'a [u8], name: &str) -> Option<&'a [u8]> {
+    pub(crate) fn elf_section<'a>(elf: &'a [u8], name: &str) -> Option<&'a [u8]> {
         // Check ELF magic.
         if elf.len() < 5 || elf.get(0..4)? != b"\x7fELF" {
             return None;
diff --git a/drivers/gpu/nova-core/fsp.rs b/drivers/gpu/nova-core/fsp.rs
index d464ad325881..15731d24d0c5 100644
--- a/drivers/gpu/nova-core/fsp.rs
+++ b/drivers/gpu/nova-core/fsp.rs
@@ -105,6 +105,84 @@ unsafe impl AsBytes for GspFmcBootParams {}
 // SAFETY: All bit patterns are valid for the primitive fields.
 unsafe impl FromBytes for GspFmcBootParams {}
 
+/// Size constraints for FSP security signatures (Hopper/Blackwell).
+const FSP_HASH_SIZE: usize = 48; // SHA-384 hash
+const FSP_PKEY_SIZE: usize = 384; // RSA-3072 public key
+const FSP_SIG_SIZE: usize = 384; // RSA-3072 signature
+
+/// Structure to hold FMC signatures.
+#[derive(Debug, Clone, Copy)]
+#[expect(dead_code)]
+pub(crate) struct FmcSignatures {
+    hash384: [u8; FSP_HASH_SIZE],
+    public_key: [u8; FSP_PKEY_SIZE],
+    signature: [u8; FSP_SIG_SIZE],
+}
+
+impl Default for FmcSignatures {
+    fn default() -> Self {
+        Self {
+            hash384: [0u8; FSP_HASH_SIZE],
+            public_key: [0u8; FSP_PKEY_SIZE],
+            signature: [0u8; FSP_SIG_SIZE],
+        }
+    }
+}
+
+/// FSP Command Response payload structure.
+/// NVDM_PAYLOAD_COMMAND_RESPONSE structure.
+#[repr(C, packed)]
+#[derive(Clone, Copy)]
+struct NvdmPayloadCommandResponse {
+    task_id: u32,
+    command_nvdm_type: u32,
+    error_code: u32,
+}
+
+/// NVDM (NVIDIA Device Management) COT (Chain of Trust) payload structure.
+/// This is the main message payload sent to FSP for Chain of Trust.
+#[repr(C, packed)]
+#[derive(Clone, Copy)]
+struct NvdmPayloadCot {
+    version: u16,
+    size: u16,
+    gsp_fmc_sysmem_offset: u64,
+    frts_sysmem_offset: u64,
+    frts_sysmem_size: u32,
+    frts_vidmem_offset: u64,
+    frts_vidmem_size: u32,
+    hash384: [u8; FSP_HASH_SIZE],
+    public_key: [u8; FSP_PKEY_SIZE],
+    signature: [u8; FSP_SIG_SIZE],
+    gsp_boot_args_sysmem_offset: u64,
+}
+
+/// Complete FSP message structure with MCTP and NVDM headers.
+#[repr(C, packed)]
+#[derive(Clone, Copy)]
+#[expect(dead_code)]
+struct FspMessage {
+    mctp_header: u32,
+    nvdm_header: u32,
+    cot: NvdmPayloadCot,
+}
+
+// SAFETY: FspMessage is a packed C struct with only integral fields.
+unsafe impl AsBytes for FspMessage {}
+
+/// Complete FSP response structure with MCTP and NVDM headers.
+#[repr(C, packed)]
+#[derive(Clone, Copy)]
+#[expect(dead_code)]
+struct FspResponse {
+    mctp_header: u32,
+    nvdm_header: u32,
+    response: NvdmPayloadCommandResponse,
+}
+
+// SAFETY: FspResponse is a packed C struct with only integral fields.
+unsafe impl FromBytes for FspResponse {}
+
 /// FSP interface for Hopper/Blackwell GPUs.
 pub(crate) struct Fsp;
 
-- 
2.53.0