[PATCH v4 27/33] gpu: nova-core: Hopper/Blackwell: larger WPR2 (GSP) heap

John Hubbard
2026-02-10T02:47:07Z

Hopper, Blackwell and later GPUs require a larger heap for WPR2.

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
drivers/gpu/nova-core/gsp/fw.rs | 57 ++++++++++++++++++++++++++-------
1 file changed, 45 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/fw.rs b/drivers/gpu/nova-core/gsp/fw.rs
index 086153edfa86..927bcee6a5a5 100644
--- a/drivers/gpu/nova-core/gsp/fw.rs
+++ b/drivers/gpu/nova-core/gsp/fw.rs
@@ -49,21 +49,41 @@ enum GspFwHeapParams {}
/// Minimum required alignment for the GSP heap.
const GSP_HEAP_ALIGNMENT: Alignment = Alignment::new::<{ 1 << 20 }>();

+// These constants override the generated bindings for architecture-specific heap sizing.
+//
+// 14MB for Hopper/Blackwell+.
+const GSP_FW_HEAP_PARAM_BASE_RM_SIZE_GH100: u64 = 14 * SZ_1M as u64;
+// 142MB client alloc for ~188MB total.
+const GSP_FW_HEAP_PARAM_CLIENT_ALLOC_SIZE_GH100: u64 = 142 * SZ_1M as u64;
+// Blackwell-specific minimum heap size (88 + 12 + 70 = 170MB)
+const GSP_FW_HEAP_SIZE_OVERRIDE_LIBOS3_BAREMETAL_MIN_MB_BLACKWELL: u64 = 170;
+
impl GspFwHeapParams {
/// Returns the amount of GSP-RM heap memory used during GSP-RM boot and initialization (up to
/// and including the first client subdevice allocation).
- fn base_rm_size(_chipset: Chipset) -> u64 {
- // TODO: this needs to be updated to return the correct value for Hopper+ once support for
- // them is added:
- // u64::from(bindings::GSP_FW_HEAP_PARAM_BASE_RM_SIZE_GH100)
- u64::from(bindings::GSP_FW_HEAP_PARAM_BASE_RM_SIZE_TU10X)
+ fn base_rm_size(chipset: Chipset) -> u64 {
+ if crate::fb::hal::fb_hal(chipset)
+ .non_wpr_heap_size()
+ .is_some()
+ {
+ GSP_FW_HEAP_PARAM_BASE_RM_SIZE_GH100
+ } else {
+ u64::from(bindings::GSP_FW_HEAP_PARAM_BASE_RM_SIZE_TU10X)
+ }
}

/// Returns the amount of heap memory required to support a single channel allocation.
- fn client_alloc_size() -> u64 {
- u64::from(bindings::GSP_FW_HEAP_PARAM_CLIENT_ALLOC_SIZE)
- .align_up(GSP_HEAP_ALIGNMENT)
- .unwrap_or(u64::MAX)
+ fn client_alloc_size(chipset: Chipset) -> u64 {
+ if crate::fb::hal::fb_hal(chipset)
+ .non_wpr_heap_size()
+ .is_some()
+ {
+ GSP_FW_HEAP_PARAM_CLIENT_ALLOC_SIZE_GH100
+ } else {
+ u64::from(bindings::GSP_FW_HEAP_PARAM_CLIENT_ALLOC_SIZE)
+ }
+ .align_up(GSP_HEAP_ALIGNMENT)
+ .expect("client_alloc_size alignment overflow")
}

/// Returns the amount of memory to reserve for management purposes for a framebuffer of size
@@ -74,7 +94,7 @@ fn management_overhead(fb_size: u64) -> u64 {
u64::from(bindings::GSP_FW_HEAP_PARAM_SIZE_PER_GB_FB)
.saturating_mul(fb_size_gb)
.align_up(GSP_HEAP_ALIGNMENT)
- .unwrap_or(u64::MAX)
+ .expect("management_overhead alignment overflow")
}
}

@@ -106,12 +126,25 @@ impl LibosParams {
* num::usize_as_u64(SZ_1M),
};

+ /// Hopper/Blackwell+ GPUs need a larger minimum heap size than the bindings specify.
+ /// The r570 bindings set LIBOS3_BAREMETAL_MIN_MB to 88MB, but Hopper/Blackwell+ actually
+ /// requires 170MB (88 + 12 + 70).
+ const LIBOS_BLACKWELL: LibosParams = LibosParams {
+ carveout_size: num::u32_as_u64(bindings::GSP_FW_HEAP_PARAM_OS_SIZE_LIBOS3_BAREMETAL),
+ allowed_heap_size: GSP_FW_HEAP_SIZE_OVERRIDE_LIBOS3_BAREMETAL_MIN_MB_BLACKWELL
+ * num::usize_as_u64(SZ_1M)
+ ..num::u32_as_u64(bindings::GSP_FW_HEAP_SIZE_OVERRIDE_LIBOS3_BAREMETAL_MAX_MB)
+ * num::usize_as_u64(SZ_1M),
+ };
+
/// Returns the libos parameters corresponding to `chipset`.
pub(crate) fn from_chipset(chipset: Chipset) -> &'static LibosParams {
if chipset < Chipset::GA102 {
&Self::LIBOS2
- } else {
+ } else if chipset < Chipset::GH100 {
&Self::LIBOS3
+ } else {
+ &Self::LIBOS_BLACKWELL
}
}

@@ -124,7 +157,7 @@ pub(crate) fn wpr_heap_size(&self, chipset: Chipset, fb_size: u64) -> u64 {
// RM boot working memory,
.saturating_add(GspFwHeapParams::base_rm_size(chipset))
// One RM client,
- .saturating_add(GspFwHeapParams::client_alloc_size())
+ .saturating_add(GspFwHeapParams::client_alloc_size(chipset))
// Overhead for memory management.
.saturating_add(GspFwHeapParams::management_overhead(fb_size))
// Clamp to the supported heap sizes.
--
2.53.0