[PATCH v7 23/23] nova-core: mm: Add BarUser to struct Gpu and create at boot
From: Joel Fernandes <joelagnelf@nvidia.com>
Date: 2026-02-18 21:21:47
Also in:
amd-gfx, dri-devel, intel-gfx, intel-xe, linux-doc, lkml, nouveau, rust-for-linux
Subsystem:
core driver for nvidia gpus [rust], drm drivers, drm drivers and common infrastructure [rust], the rest · Maintainers:
Danilo Krummrich, Alexandre Courbot, David Airlie, Simona Vetter, Alice Ryhl, Linus Torvalds
Add a BarUser field to struct Gpu and eagerly create it during GPU initialization. The BarUser provides the BAR1 user interface for CPU access to GPU virtual memory through the GPU's MMU. The BarUser is initialized using BAR1 PDE base address from GSP static info, MMU version and BAR1 size obtained from platform device. Cc: Nikola Djukic <redacted> Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com> --- drivers/gpu/nova-core/gpu.rs | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
index 670a2a89c6ec..159ccea8464a 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs@@ -26,7 +26,12 @@ commands::GetGspStaticInfoReply, Gsp, // }, - mm::GpuMm, + mm::{ + bar_user::BarUser, + pagetable::MmuVersion, + GpuMm, + VramAddress, // + }, regs, };
@@ -35,6 +40,7 @@ struct BootParams { usable_vram_start: u64, usable_vram_size: u64, + bar1_pde_base: u64, } macro_rules! define_chipset {
@@ -272,6 +278,8 @@ pub(crate) struct Gpu { gsp: Gsp, /// Static GPU information from GSP. gsp_static_info: GetGspStaticInfoReply, + /// BAR1 user interface for CPU access to GPU virtual memory. + bar_user: BarUser, } impl Gpu {
@@ -285,6 +293,7 @@ pub(crate) fn new<'a>( let boot_params: Cell<BootParams> = Cell::new(BootParams { usable_vram_start: 0, usable_vram_size: 0, + bar1_pde_base: 0, }); try_pin_init!(Self {
@@ -329,6 +338,7 @@ pub(crate) fn new<'a>( boot_params.set(BootParams { usable_vram_start: usable_vram.start, usable_vram_size: usable_vram.end - usable_vram.start, + bar1_pde_base: info.bar1_pde_base(), }); info
@@ -345,6 +355,16 @@ pub(crate) fn new<'a>( })? }, + // Create BAR1 user interface for CPU access to GPU virtual memory. + // Uses the BAR1 PDE base from GSP and full BAR1 size for VA space. + bar_user: { + let params = boot_params.get(); + let pdb_addr = VramAddress::new(params.bar1_pde_base); + let mmu_version = MmuVersion::from(spec.chipset.arch()); + let bar1_size = pdev.resource_len(1)?; + BarUser::new(pdb_addr, mmu_version, bar1_size)? + }, + bar: devres_bar, }) }
--
2.34.1