[PATCH v8 10/16] gpu: nova-core: gsp: Create rmargs

Alexandre Courbot
2025-11-07T23:43:11Z

From: Alistair Popple <apopple at nvidia.com>

Initialise the GSP resource manager arguments (rmargs) which provides
initialisation parameters to the GSP firmware during boot. The rmargs
structure contains arguments to configure the GSP message/command queue
location.

These are mapped for coherent DMA and added to the libos data structure
for access when booting GSP.

Co-developed-by: Alexandre Courbot <acourbot at nvidia.com>
Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
Signed-off-by: Alistair Popple <apopple at nvidia.com>
---
 drivers/gpu/nova-core/gsp.rs      | 12 +++++++++++
 drivers/gpu/nova-core/gsp/cmdq.rs | 26 ++++++++++++++++++++++-
 drivers/gpu/nova-core/gsp/fw.rs   | 44 ++++++++++++++++++++++++++++++++++++++-
 3 files changed, 80 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp.rs b/drivers/gpu/nova-core/gsp.rs
index 46b3e4819473..bc897e57f396 100644
--- a/drivers/gpu/nova-core/gsp.rs
+++ b/drivers/gpu/nova-core/gsp.rs
@@ -15,6 +15,7 @@
 pub(crate) mod cmdq;
 mod fw;

+use fw::GspArgumentsCached;
 use fw::LibosMemoryRegionInitArgument;

 pub(crate) use fw::{GspFwWprMeta, LibosParams};
@@ -101,6 +102,8 @@ pub(crate) struct Gsp {
     logrm: LogBuffer,
     /// Command queue.
     pub(crate) cmdq: Cmdq,
+    /// RM arguments.
+    rmargs: CoherentAllocation<GspArgumentsCached>,
 }

 impl Gsp {
@@ -127,11 +130,20 @@ pub(crate) fn new(pdev:
&pci::Device<device::Bound>) -> Result<impl PinInit<Self

         let cmdq = Cmdq::new(dev)?;

+        let rmargs =
CoherentAllocation::<GspArgumentsCached>::alloc_coherent(
+            dev,
+            1,
+            GFP_KERNEL | __GFP_ZERO,
+        )?;
+        dma_write!(rmargs[0] = fw::GspArgumentsCached::new(&cmdq))?;
+        dma_write!(libos[3] =
LibosMemoryRegionInitArgument::new("RMARGS", &rmargs))?;
+
         Ok(try_pin_init!(Self {
             libos,
             loginit,
             logintr,
             logrm,
+            rmargs,
             cmdq,
         }))
     }
diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs
b/drivers/gpu/nova-core/gsp/cmdq.rs
index 8461738b1110..4a6c0e14ed53 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -11,7 +11,10 @@

 use kernel::{
     device,
-    dma::CoherentAllocation,
+    dma::{
+        CoherentAllocation,
+        DmaAddress, //
+    },
     dma_write,
     io::poll::read_poll_timeout,
     prelude::*,
@@ -33,6 +36,7 @@
             MsgqTxHeader, //
         },
         PteArray,
+        GSP_PAGE_SHIFT,
         GSP_PAGE_SIZE, //
     },
     num,
@@ -378,6 +382,22 @@ pub(crate) struct Cmdq {
 }

 impl Cmdq {
+    /// Offset of the data after the PTEs.
+    const POST_PTE_OFFSET: usize = core::mem::offset_of!(GspMem, cpuq);
+
+    /// Offset of command queue ring buffer.
+    pub(crate) const CMDQ_OFFSET: usize = core::mem::offset_of!(GspMem, cpuq)
+        + core::mem::offset_of!(Msgq, msgq)
+        - Self::POST_PTE_OFFSET;
+
+    /// Offset of message queue ring buffer.
+    pub(crate) const STATQ_OFFSET: usize = core::mem::offset_of!(GspMem, gspq)
+        + core::mem::offset_of!(Msgq, msgq)
+        - Self::POST_PTE_OFFSET;
+
+    /// Number of page table entries for the GSP shared region.
+    pub(crate) const NUM_PTES: usize = size_of::<GspMem>() >>
GSP_PAGE_SHIFT;
+
     /// Creates a new command queue for `dev`.
     pub(crate) fn new(dev: &device::Device<device::Bound>) ->
Result<Cmdq> {
         let gsp_mem = DmaGspMem::new(dev)?;
@@ -581,4 +601,8 @@ pub(crate) fn receive_msg_from_gsp<M: MessageFromGsp,
R>(

         result
     }
+
+    pub(crate) fn dma_handle(&self) -> DmaAddress {
+        self.gsp_mem.0.dma_handle()
+    }
 }
diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index ceda61c99b92..b083a6a5754c 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -31,7 +31,10 @@
     fb::FbLayout,
     firmware::gsp::GspFirmware,
     gpu::Chipset,
-    gsp::GSP_PAGE_SIZE,
+    gsp::{
+        cmdq::Cmdq, //
+        GSP_PAGE_SIZE,
+    },
     num::{
         self,
         FromSafeCast, //
@@ -568,3 +571,42 @@ unsafe impl AsBytes for GspMsgElement {}
 // SAFETY: This struct only contains integer types for which all bit patterns
 // are valid.
 unsafe impl FromBytes for GspMsgElement {}
+
+/// Arguments for GSP startup.
+#[repr(transparent)]
+pub(crate) struct GspArgumentsCached(bindings::GSP_ARGUMENTS_CACHED);
+
+impl GspArgumentsCached {
+    /// Creates the arguments for starting the GSP up using `cmdq` as its
command queue.
+    pub(crate) fn new(cmdq: &Cmdq) -> Self {
+        Self(bindings::GSP_ARGUMENTS_CACHED {
+            messageQueueInitArguments: MessageQueueInitArguments::new(cmdq).0,
+            bDmemStack: 1,
+            ..Default::default()
+        })
+    }
+}
+
+// SAFETY: Padding is explicit and will not contain uninitialized data.
+unsafe impl AsBytes for GspArgumentsCached {}
+
+// SAFETY: This struct only contains integer types for which all bit patterns
+// are valid.
+unsafe impl FromBytes for GspArgumentsCached {}
+
+/// Init arguments for the message queue.
+#[repr(transparent)]
+struct MessageQueueInitArguments(bindings::MESSAGE_QUEUE_INIT_ARGUMENTS);
+
+impl MessageQueueInitArguments {
+    /// Creates a new init arguments structure for `cmdq`.
+    fn new(cmdq: &Cmdq) -> Self {
+        Self(bindings::MESSAGE_QUEUE_INIT_ARGUMENTS {
+            sharedMemPhysAddr: cmdq.dma_handle(),
+            pageTableEntryCount: num::usize_into_u32::<{ Cmdq::NUM_PTES
}>(),
+            cmdQueueOffset: num::usize_as_u64(Cmdq::CMDQ_OFFSET),
+            statQueueOffset: num::usize_as_u64(Cmdq::STATQ_OFFSET),
+            ..Default::default()
+        })
+    }
+}

--
2.51.2