Add `total_fb_end()` to `GspStaticConfigInfo` that computes the
exclusive end address of the highest valid FB region covering both
usable and GSP-reserved areas.

This allows callers to know the full physical VRAM extent, not just
the allocatable portion.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
---
 drivers/gpu/nova-core/gsp/commands.rs    | 6 ++++++
 drivers/gpu/nova-core/gsp/fw/commands.rs | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/drivers/gpu/nova-core/gsp/commands.rs b/drivers/gpu/nova-core/gsp/commands.rs
index 41742c1633c8..5e0649024637 100644
--- a/drivers/gpu/nova-core/gsp/commands.rs
+++ b/drivers/gpu/nova-core/gsp/commands.rs
@@ -196,6 +196,9 @@ pub(crate) struct GetGspStaticInfoReply {
     /// Usable FB (VRAM) region for driver memory allocation.
     #[expect(dead_code)]
     pub(crate) usable_fb_region: Range<u64>,
+    /// End of VRAM.
+    #[expect(dead_code)]
+    pub(crate) total_fb_end: u64,
 }
 
 impl MessageFromGsp for GetGspStaticInfoReply {
@@ -209,9 +212,12 @@ fn read(
     ) -> Result<Self, Self::InitError> {
         let (base, size) = msg.first_usable_fb_region().ok_or(ENODEV)?;
 
+        let total_fb_end = msg.total_fb_end().ok_or(ENODEV)?;
+
         Ok(GetGspStaticInfoReply {
             gpu_name: msg.gpu_name_str(),
             usable_fb_region: base..base.saturating_add(size),
+            total_fb_end,
         })
     }
 }
diff --git a/drivers/gpu/nova-core/gsp/fw/commands.rs b/drivers/gpu/nova-core/gsp/fw/commands.rs
index 9fffa74d03f9..46932d5c8c1d 100644
--- a/drivers/gpu/nova-core/gsp/fw/commands.rs
+++ b/drivers/gpu/nova-core/gsp/fw/commands.rs
@@ -163,6 +163,13 @@ pub(crate) fn first_usable_fb_region(&self) -> Option<(u64, u64)> {
             }
         })
     }
+
+    /// Compute the end of physical VRAM from all FB regions.
+    pub(crate) fn total_fb_end(&self) -> Option<u64> {
+        self.fb_regions()
+            .map(|reg| reg.limit.saturating_add(1))
+            .max()
+    }
 }
 
 // SAFETY: Padding is explicit and will not contain uninitialized data.
-- 
2.34.1