gpu: nova-core: add ImemNonSecure section infrastructure

The GSP booter firmware in Turing and GA100 includes a third memory
section called ImemNonSecure, which is non-secure IMEM.  This section
must be loaded separately from DMEM and secure IMEM, but only if it
actually exists.

Signed-off-by: Timur Tabi <ttabi@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patch.msgid.link/20260122222848.2555890-3-ttabi@nvidia.com
[acourbot@nvidia.com: add `debug_assert`.]
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>

drivers/gpu/nova-core/falcon.rs

@@ -242,6 +242,9 @@ fn from(value: PeregrineCoreSelect) -> Self {
 pub(crate) enum FalconMem {
     /// Secure Instruction Memory.
     ImemSecure,
+    /// Non-Secure Instruction Memory.
+    #[expect(unused)]
+    ImemNonSecure,
     /// Data Memory.
     Dmem,
 }
@@ -351,6 +354,10 @@ pub(crate) trait FalconLoadParams {
     /// Returns the load parameters for Secure `IMEM`.
     fn imem_sec_load_params(&self) -> FalconLoadTarget;
 
+    /// Returns the load parameters for Non-Secure `IMEM`,
+    /// used only on Turing and GA100.
+    fn imem_ns_load_params(&self) -> Option<FalconLoadTarget>;
+
     /// Returns the load parameters for `DMEM`.
     fn dmem_load_params(&self) -> FalconLoadTarget;
 
@@ -460,7 +467,9 @@ fn dma_wr<F: FalconFirmware<Target = E>>(
         //
         // For DMEM we can fold the start offset into the DMA handle.
         let (src_start, dma_start) = match target_mem {
-            FalconMem::ImemSecure => (load_offsets.src_start, fw.dma_handle()),
+            FalconMem::ImemSecure | FalconMem::ImemNonSecure => {
+                (load_offsets.src_start, fw.dma_handle())
+            }
             FalconMem::Dmem => (
                 0,
                 fw.dma_handle_with_offset(load_offsets.src_start.into_safe_cast())?,
@@ -517,7 +526,7 @@ fn dma_wr<F: FalconFirmware<Target = E>>(
 
         let cmd = regs::NV_PFALCON_FALCON_DMATRFCMD::default()
             .set_size(DmaTrfCmdSize::Size256B)
-            .set_imem(target_mem == FalconMem::ImemSecure)
+            .set_imem(target_mem != FalconMem::Dmem)
             .set_sec(if sec { 1 } else { 0 });
 
         for pos in (0..num_transfers).map(|i| i * DMA_LEN) {
@@ -546,6 +555,13 @@ fn dma_wr<F: FalconFirmware<Target = E>>(
 
     /// Perform a DMA load into `IMEM` and `DMEM` of `fw`, and prepare the falcon to run it.
     pub(crate) fn dma_load<F: FalconFirmware<Target = E>>(&self, bar: &Bar0, fw: &F) -> Result {
+        // The Non-Secure section only exists on firmware used by Turing and GA100, and
+        // those platforms do not use DMA.
+        if fw.imem_ns_load_params().is_some() {
+            debug_assert!(false);
+            return Err(EINVAL);
+        }
+
         self.dma_reset(bar);
         regs::NV_PFALCON_FBIF_TRANSCFG::update(bar, &E::ID, 0, |v| {
             v.set_target(FalconFbifTarget::CoherentSysmem)

drivers/gpu/nova-core/firmware/booter.rs

@@ -253,6 +253,9 @@ impl<'a> FirmwareSignature<BooterFirmware> for BooterSignature<'a> {}
 pub(crate) struct BooterFirmware {
     // Load parameters for Secure `IMEM` falcon memory.
     imem_sec_load_target: FalconLoadTarget,
+    // Load parameters for Non-Secure `IMEM` falcon memory,
+    // used only on Turing and GA100
+    imem_ns_load_target: Option<FalconLoadTarget>,
     // Load parameters for `DMEM` falcon memory.
     dmem_load_target: FalconLoadTarget,
     // BROM falcon parameters.
@@ -359,6 +362,8 @@ pub(crate) fn new(
                 dst_start: 0,
                 len: app0.len,
             },
+            // Exists only in the booter image for Turing and GA100
+            imem_ns_load_target: None,
             dmem_load_target: FalconLoadTarget {
                 src_start: load_hdr.os_data_offset,
                 dst_start: 0,
@@ -375,6 +380,10 @@ fn imem_sec_load_params(&self) -> FalconLoadTarget {
         self.imem_sec_load_target.clone()
     }
 
+    fn imem_ns_load_params(&self) -> Option<FalconLoadTarget> {
+        self.imem_ns_load_target.clone()
+    }
+
     fn dmem_load_params(&self) -> FalconLoadTarget {
         self.dmem_load_target.clone()
     }

drivers/gpu/nova-core/firmware/fwsec.rs

@@ -232,6 +232,11 @@ fn imem_sec_load_params(&self) -> FalconLoadTarget {
         }
     }
 
+    fn imem_ns_load_params(&self) -> Option<FalconLoadTarget> {
+        // Only used on Turing and GA100, so return None for now
+        None
+    }
+
     fn dmem_load_params(&self) -> FalconLoadTarget {
         FalconLoadTarget {
             src_start: self.desc.imem_load_size,