[PATCH v6 0/2] rust, nova-core: add SizeConstants trait for SZ_* constants

From: John Hubbard

Date: Fri Apr 10 2026 - 22:41:44 EST


Changes in v6:

* Rebased onto Alex Courbot's drm-rust-next-staging branch[1], which now
includes the prerequisites, so this is only 2 patches instead of 3.

Sending this because it makes the upcoming Blackwell v10 posting
cleaner.

Changes in v5:
* Changed the subject line of this cover letter to not use the old
DeviceSize name.

* Collected Reviewed-by tags from Alexandre Courbot and Joel
Fernandes, and Acked-by from Gary Guo.

* Added a new patch 3/3 with a todo.rst entry for device address
type wrappers and a marker trait, as discussed with Danilo.

* Rebased onto latest drm-rust-next.

Changes in v4:
* Renamed the trait from DeviceSize to SizeConstants.

* Added backticks and trailing periods to all hex-value doc comments
on the SZ_* constants.

* Removed redundant type annotations from doc-test examples.

* Used a `use` import for PAGE_SIZE in the module-level doc-test
instead of a fully qualified path.

* Rewrote doc-test comments to clarify the distinction between
module-level constants (no type qualifier) and trait associated
constants (type qualifier required).

* Added Reviewed-by from Eliot Courtney.

Changes in v3:
* Dropped the Alignment::from_u64() patch.

* Reworked define_sizes! macro to accept target types as arguments
(define_sizes!(u32, u64, usize)) using recursive macro arms,
instead of hardcoding impls for u32 and u64. Overflow checking
uses u128 casts so the same assert works for any ("reasonable")
target type.

* Added usize to the DeviceSize implementations, so the trait
covers u32, u64, and usize.

* Hex values for each constant are now proper doc-comments
(forwarded via macro meta), instead of inline comments.

* Rebased onto latest drm-rust-next.

Changes in v2:
* Replaced flat SZ_*_U64 constants with a DeviceSize trait that
provides SZ_* as associated constants on u32 and u64.

* A define_sizes! macro generates everything from one list of names.

* Added Alignment::from_u64() so alignment values can be constructed
from DeviceSize constants without falling back to usize variants.

* Rebased onto drm-rust-next. No longer depends on the Blackwell
patchset.

[1] https://github.com/Gnurou/linux/commits/drm-rust-next-staging/

v1 is here:
https://lore.kernel.org/20260310023145.120037-1-jhubbard@xxxxxxxxxx

John Hubbard (2):
gpu: nova-core: use SizeConstants trait for u64 size constants
gpu: nova-core: add task for device address type wrappers

Documentation/gpu/nova/core/todo.rst | 14 ++++++++++++++
drivers/gpu/nova-core/fb.rs | 21 +++++++++------------
drivers/gpu/nova-core/gsp/fw.rs | 15 +++++++--------
drivers/gpu/nova-core/regs.rs | 7 +++----
4 files changed, 33 insertions(+), 24 deletions(-)


base-commit: 8884dbc1fd174315b406027375bb7a4b211a8fae
--
2.53.0