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

Joel Fernandes
2026-01-20T20:44:20Z

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