[PATCH v11 04/22] gpu: nova-core: Hopper/Blackwell: larger non-WPR heap

[John Hubbard <jhubbard@nvidia.com>]

Hopper and Blackwell need a larger non-WPR heap than the 1 MiB that
earlier architectures use. Hopper and Blackwell GB10x need 2 MiB, while
Blackwell GB20x needs 2 MiB + 128 KiB. Because GB10x and GB20x diverge
here, give each Blackwell family its own framebuffer HAL and select the
non-WPR heap size per chipset family.

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 drivers/gpu/nova-core/fb.rs           |  5 ++-
 drivers/gpu/nova-core/fb/hal.rs       | 16 +++++++--
 drivers/gpu/nova-core/fb/hal/gb100.rs |  9 +++--
 drivers/gpu/nova-core/fb/hal/gb202.rs | 52 +++++++++++++++++++++++++++
 drivers/gpu/nova-core/fb/hal/gh100.rs | 10 +++++-
 5 files changed, 84 insertions(+), 8 deletions(-)
 create mode 100644 drivers/gpu/nova-core/fb/hal/gb202.rs

diff --git a/drivers/gpu/nova-core/fb.rs b/drivers/gpu/nova-core/fb.rs
index d7a4dc944131..0aaee718c2c3 100644
--- a/drivers/gpu/nova-core/fb.rs
+++ b/drivers/gpu/nova-core/fb.rs
@@ -252,9 +252,8 @@ pub(crate) fn new(chipset: Chipset, bar: &Bar0, gsp_fw: &GspFirmware) -> Result<
         };
 
         let heap = {
-            const HEAP_SIZE: u64 = u64::SZ_1M;
-
-            FbRange(wpr2.start - HEAP_SIZE..wpr2.start)
+            let heap_size = u64::from(hal.non_wpr_heap_size());
+            FbRange(wpr2.start - heap_size..wpr2.start)
         };
 
         Ok(Self {
diff --git a/drivers/gpu/nova-core/fb/hal.rs b/drivers/gpu/nova-core/fb/hal.rs
index e6ac55bba9b9..acb934f9aa9f 100644
--- a/drivers/gpu/nova-core/fb/hal.rs
+++ b/drivers/gpu/nova-core/fb/hal.rs
@@ -1,7 +1,10 @@
 // SPDX-License-Identifier: GPL-2.0
 // SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 
-use kernel::prelude::*;
+use kernel::{
+    prelude::*,
+    sizes::SizeConstants, //
+};
 
 use crate::{
     driver::Bar0,
@@ -14,6 +17,7 @@
 mod ga100;
 mod ga102;
 mod gb100;
+mod gb202;
 mod gh100;
 mod tu102;
 
@@ -37,6 +41,13 @@ pub(crate) trait FbHal {
 
     /// Returns the FRTS size, in bytes.
     fn frts_size(&self) -> u64;
+
+    /// Returns the non-WPR heap size for this chipset, in bytes.
+    ///
+    /// Older architectures use 1 MiB. Hopper and Blackwell override this.
+    fn non_wpr_heap_size(&self) -> u32 {
+        u32::SZ_1M
+    }
 }
 
 /// Returns the HAL corresponding to `chipset`.
@@ -46,6 +57,7 @@ pub(super) fn fb_hal(chipset: Chipset) -> &'static dyn FbHal {
         Architecture::Ampere if chipset == Chipset::GA100 => ga100::GA100_HAL,
         Architecture::Ampere | Architecture::Ada => ga102::GA102_HAL,
         Architecture::Hopper => gh100::GH100_HAL,
-        Architecture::BlackwellGB10x | Architecture::BlackwellGB20x => gb100::GB100_HAL,
+        Architecture::BlackwellGB10x => gb100::GB100_HAL,
+        Architecture::BlackwellGB20x => gb202::GB202_HAL,
     }
 }
diff --git a/drivers/gpu/nova-core/fb/hal/gb100.rs b/drivers/gpu/nova-core/fb/hal/gb100.rs
index c78027c26a9e..8d63350abf8a 100644
--- a/drivers/gpu/nova-core/fb/hal/gb100.rs
+++ b/drivers/gpu/nova-core/fb/hal/gb100.rs
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 // SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 
-//! Blackwell framebuffer HAL.
+//! Blackwell GB10x framebuffer HAL.
 
 use kernel::{
     prelude::*,
@@ -20,7 +20,7 @@
 
 struct Gb100;
 
-const fn pmu_reserved_size_gb100() -> u32 {
+pub(super) const fn pmu_reserved_size_gb100() -> u32 {
     usize_into_u32::<{ const_align_up(SZ_8M + SZ_16M + SZ_4K, Alignment::new::<SZ_128K>()).unwrap() }>(
     )
 }
@@ -48,6 +48,11 @@ fn pmu_reserved_size(&self) -> u32 {
         pmu_reserved_size_gb100()
     }
 
+    fn non_wpr_heap_size(&self) -> u32 {
+        // Non-WPR heap for GB10x (see Open RM: kgspGetNonWprHeapSize, GB100/GB102).
+        u32::SZ_2M
+    }
+
     fn frts_size(&self) -> u64 {
         super::tu102::frts_size_tu102()
     }
diff --git a/drivers/gpu/nova-core/fb/hal/gb202.rs b/drivers/gpu/nova-core/fb/hal/gb202.rs
new file mode 100644
index 000000000000..542c1d7429e9
--- /dev/null
+++ b/drivers/gpu/nova-core/fb/hal/gb202.rs
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0
+// SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
+//! Blackwell GB20x framebuffer HAL.
+
+use kernel::{
+    prelude::*,
+    sizes::SizeConstants, //
+};
+
+use crate::{
+    driver::Bar0,
+    fb::hal::FbHal, //
+};
+
+struct Gb202;
+
+impl FbHal for Gb202 {
+    fn read_sysmem_flush_page(&self, bar: &Bar0) -> u64 {
+        super::ga100::read_sysmem_flush_page_ga100(bar)
+    }
+
+    fn write_sysmem_flush_page(&self, bar: &Bar0, addr: u64) -> Result {
+        super::ga100::write_sysmem_flush_page_ga100(bar, addr);
+
+        Ok(())
+    }
+
+    fn supports_display(&self, bar: &Bar0) -> bool {
+        super::ga100::display_enabled_ga100(bar)
+    }
+
+    fn vidmem_size(&self, bar: &Bar0) -> u64 {
+        super::ga102::vidmem_size_ga102(bar)
+    }
+
+    fn pmu_reserved_size(&self) -> u32 {
+        super::gb100::pmu_reserved_size_gb100()
+    }
+
+    fn non_wpr_heap_size(&self) -> u32 {
+        // Non-WPR heap for GB20x (see Open RM: kgspGetNonWprHeapSize, GB202+).
+        u32::SZ_2M + u32::SZ_128K
+    }
+
+    fn frts_size(&self) -> u64 {
+        super::tu102::frts_size_tu102()
+    }
+}
+
+const GB202: Gb202 = Gb202;
+pub(super) const GB202_HAL: &dyn FbHal = &GB202;
diff --git a/drivers/gpu/nova-core/fb/hal/gh100.rs b/drivers/gpu/nova-core/fb/hal/gh100.rs
index c122ac2091f8..8f79c72b1823 100644
--- a/drivers/gpu/nova-core/fb/hal/gh100.rs
+++ b/drivers/gpu/nova-core/fb/hal/gh100.rs
@@ -1,7 +1,10 @@
 // SPDX-License-Identifier: GPL-2.0
 // SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 
-use kernel::prelude::*;
+use kernel::{
+    prelude::*,
+    sizes::SizeConstants, //
+};
 
 use crate::{
     driver::Bar0,
@@ -33,6 +36,11 @@ fn pmu_reserved_size(&self) -> u32 {
         super::tu102::pmu_reserved_size_tu102()
     }
 
+    fn non_wpr_heap_size(&self) -> u32 {
+        // Non-WPR heap for Hopper (see Open RM: kgspCalculateFbLayout_GH100).
+        u32::SZ_2M
+    }
+
     fn frts_size(&self) -> u64 {
         super::tu102::frts_size_tu102()
     }
-- 
2.54.0