[PATCH v8 21/25] gpu: nova-core: gsp: Add BAR1 PDE base accessors

[Joel Fernandes]

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.

Cc: Nikola Djukic <ndjukic@xxxxxxxxxx>
Signed-off-by: Joel Fernandes <joelagnelf@xxxxxxxxxx>
---
 drivers/gpu/nova-core/gsp/commands.rs    | 8 ++++++++
 drivers/gpu/nova-core/gsp/fw/commands.rs | 8 ++++++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/gpu/nova-core/gsp/commands.rs b/drivers/gpu/nova-core/gsp/commands.rs
index fc9ba08f9f8d..22bd61e2a67e 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 [`GetGspStaticInfo`] command.
 pub(crate) struct GetGspStaticInfoReply {
     gpu_name: [u8; 64],
+    bar1_pde_base: u64,
     /// First usable FB region `(base, size)` for memory allocation.
     usable_fb_region: Option<(u64, u64)>,
 }
@@ -204,6 +205,7 @@ fn read(
     ) -> Result<Self, Self::InitError> {
         Ok(GetGspStaticInfoReply {
             gpu_name: msg.gpu_name_str(),
+            bar1_pde_base: msg.bar1_pde_base(),
             usable_fb_region: msg.first_usable_fb_region(),
         })
     }
@@ -232,6 +234,12 @@ pub(crate) fn gpu_name(&self) -> core::result::Result<&str, GpuNameError> {
             .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
+    }
+
     /// Returns the usable FB region `(base, size)` for driver allocation which is
     /// already retrieved from the GSP.
     pub(crate) fn usable_fb_region(&self) -> Option<(u64, u64)> {
diff --git a/drivers/gpu/nova-core/gsp/fw/commands.rs b/drivers/gpu/nova-core/gsp/fw/commands.rs
index ff771a4aba4f..307f48670e6d 100644
--- a/drivers/gpu/nova-core/gsp/fw/commands.rs
+++ b/drivers/gpu/nova-core/gsp/fw/commands.rs
@@ -116,6 +116,14 @@ impl GspStaticConfigInfo {
         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
+    }
+
     /// Extract the first usable FB region from GSP firmware data.
     ///
     /// Returns the first region suitable for driver memory allocation as a `(base, size)` tuple.
-- 
2.34.1