[PATCH RFC v6 08/26] nova-core: gsp: Add BAR1 PDE base accessors

[Joel Fernandes <joelagnelf@nvidia.com>]

Add accessor methods to GspStaticConfigInfo for retrieving the BAR1 Page
Directory Entry base addresses from GSP-RM firmware.

These addresses point to the root page tables for BAR1 virtual memory spaces.
The page tables are set up by GSP-RM during GPU initialization.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
---
 drivers/gpu/nova-core/driver.rs          | 1 +
 drivers/gpu/nova-core/gsp/commands.rs    | 8 ++++++++
 drivers/gpu/nova-core/gsp/fw/commands.rs | 8 ++++++++
 3 files changed, 17 insertions(+)

diff --git a/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs
index d8b2e967ba4c..f30ffa45cf13 100644
--- a/drivers/gpu/nova-core/driver.rs
+++ b/drivers/gpu/nova-core/driver.rs
@@ -42,6 +42,7 @@ pub(crate) struct NovaCore {
 const GPU_DMA_BITS: u32 = 47;
 
 pub(crate) type Bar0 = pci::Bar<BAR0_SIZE>;
+#[expect(dead_code)]
 pub(crate) type Bar1 = pci::Bar<BAR1_SIZE>;
 
 kernel::pci_device_table!(
diff --git a/drivers/gpu/nova-core/gsp/commands.rs b/drivers/gpu/nova-core/gsp/commands.rs
index c8430a076269..7b5025cba106 100644
--- a/drivers/gpu/nova-core/gsp/commands.rs
+++ b/drivers/gpu/nova-core/gsp/commands.rs
@@ -189,6 +189,7 @@ fn init(&self) -> impl Init<Self::Command, Self::InitError> {
 /// The reply from the GSP to the [`GetGspInfo`] command.
 pub(crate) struct GetGspStaticInfoReply {
     gpu_name: [u8; 64],
+    bar1_pde_base: u64,
 }
 
 impl MessageFromGsp for GetGspStaticInfoReply {
@@ -202,6 +203,7 @@ fn read(
     ) -> Result<Self, Self::InitError> {
         Ok(GetGspStaticInfoReply {
             gpu_name: msg.gpu_name_str(),
+            bar1_pde_base: msg.bar1_pde_base(),
         })
     }
 }
@@ -228,6 +230,12 @@ pub(crate) fn gpu_name(&self) -> core::result::Result<&str, GpuNameError> {
             .to_str()
             .map_err(GpuNameError::InvalidUtf8)
     }
+
+    /// Returns the BAR1 Page Directory Entry base address.
+    #[expect(dead_code)]
+    pub(crate) fn bar1_pde_base(&self) -> u64 {
+        self.bar1_pde_base
+    }
 }
 
 /// Send the [`GetGspInfo`] command and awaits for its reply.
diff --git a/drivers/gpu/nova-core/gsp/fw/commands.rs b/drivers/gpu/nova-core/gsp/fw/commands.rs
index 21be44199693..f069f4092911 100644
--- a/drivers/gpu/nova-core/gsp/fw/commands.rs
+++ b/drivers/gpu/nova-core/gsp/fw/commands.rs
@@ -114,6 +114,14 @@ impl GspStaticConfigInfo {
     pub(crate) fn gpu_name_str(&self) -> [u8; 64] {
         self.0.gpuNameString
     }
+
+    /// Returns the BAR1 Page Directory Entry base address.
+    ///
+    /// This is the root page table address for BAR1 virtual memory,
+    /// set up by GSP-RM firmware.
+    pub(crate) fn bar1_pde_base(&self) -> u64 {
+        self.0.bar1PdeBase
+    }
 }
 
 // SAFETY: Padding is explicit and will not contain uninitialized data.
-- 
2.34.1