[PATCH RFC v6 15/26] nova-core: mm: Add GpuMm centralized memory manager

Joel Fernandes
2026-01-20T20:44:23Z

Introduce GpuMm as the centralized GPU memory manager that owns:
- Buddy allocator for VRAM allocation.
- PRAMIN window for direct VRAM access.
- TLB manager for translation buffer operations.

This provides clean ownership model where GpuMm provides accessor
methods for its components that can be used for memory management
operations.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
---
drivers/gpu/nova-core/gpu.rs | 14 +++++++++
drivers/gpu/nova-core/mm/mod.rs | 55 ++++++++++++++++++++++++++++++++-
2 files changed, 68 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
index 9b042ef1a308..572e6d4502bc 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -4,8 +4,10 @@
device,
devres::Devres,
fmt,
+ gpu::buddy::GpuBuddyParams,
pci,
prelude::*,
+ sizes::{SZ_1M, SZ_4K},
sync::Arc, //
};

@@ -19,6 +21,7 @@
fb::SysmemFlush,
gfw,
gsp::Gsp,
+ mm::GpuMm,
regs,
};

@@ -249,6 +252,8 @@ pub(crate) struct Gpu {
gsp_falcon: Falcon<GspFalcon>,
/// SEC2 falcon instance, used for GSP boot up and cleanup.
sec2_falcon: Falcon<Sec2Falcon>,
+ /// GPU memory manager owning memory management resources.
+ mm: GpuMm,
/// GSP runtime data. Temporarily an empty placeholder.
#[pin]
gsp: Gsp,
@@ -281,6 +286,15 @@ pub(crate) fn new<'a>(

sec2_falcon: Falcon::new(pdev.as_ref(), spec.chipset)?,

+ // Create GPU memory manager owning memory management resources.
+ // This will be initialized with the usable VRAM region from GSP in a later
+ // patch. For now, we use a placeholder of 1MB.
+ mm: GpuMm::new(devres_bar.clone(), GpuBuddyParams {
+ base_offset_bytes: 0,
+ physical_memory_size_bytes: SZ_1M as u64,
+ chunk_size_bytes: SZ_4K as u64,
+ })?,
+
gsp <- Gsp::new(pdev),

_: { gsp.boot(pdev, bar, spec.chipset, gsp_falcon, sec2_falcon)? },
diff --git a/drivers/gpu/nova-core/mm/mod.rs b/drivers/gpu/nova-core/mm/mod.rs
index 39635f2d0156..56c72bf51431 100644
--- a/drivers/gpu/nova-core/mm/mod.rs
+++ b/drivers/gpu/nova-core/mm/mod.rs
@@ -8,7 +8,60 @@
pub(crate) mod pramin;
pub(crate) mod tlb;

-use kernel::sizes::SZ_4K;
+use kernel::{
+ devres::Devres,
+ gpu::buddy::{
+ GpuBuddy,
+ GpuBuddyParams, //
+ },
+ prelude::*,
+ sizes::SZ_4K,
+ sync::Arc, //
+};
+
+use crate::driver::Bar0;
+
+pub(crate) use tlb::Tlb;
+
+/// GPU Memory Manager - owns all core MM components.
+///
+/// Provides centralized ownership of memory management resources:
+/// - [`GpuBuddy`] allocator for VRAM page table allocation.
+/// - [`pramin::Window`] for direct VRAM access.
+/// - [`Tlb`] manager for translation buffer flush operations.
+///
+/// No pinning required, all fields manage their own pinning internally.
+pub(crate) struct GpuMm {
+ buddy: GpuBuddy,
+ pramin: pramin::Window,
+ tlb: Tlb,
+}
+
+impl GpuMm {
+ /// Create a new `GpuMm` object.
+ pub(crate) fn new(bar: Arc<Devres<Bar0>>, buddy_params: GpuBuddyParams) -> Result<Self> {
+ Ok(Self {
+ buddy: GpuBuddy::new(buddy_params)?,
+ pramin: pramin::Window::new(bar.clone())?,
+ tlb: Tlb::new(bar),
+ })
+ }
+
+ /// Access the [`GpuBuddy`] allocator.
+ pub(crate) fn buddy(&self) -> &GpuBuddy {
+ &self.buddy
+ }
+
+ /// Access the [`pramin::Window`].
+ pub(crate) fn pramin(&mut self) -> &mut pramin::Window {
+ &mut self.pramin
+ }
+
+ /// Access the [`Tlb`] manager.
+ pub(crate) fn tlb(&self) -> &Tlb {
+ &self.tlb
+ }
+}

/// Page size in bytes (4 KiB).
pub(crate) const PAGE_SIZE: usize = SZ_4K;
--
2.34.1