| From: |
| Alexandre Courbot <acourbot-AT-nvidia.com> |
| To: |
| Miguel Ojeda <ojeda-AT-kernel.org>, Nathan Chancellor <nathan-AT-kernel.org>, Nicolas Schier <nsc-AT-kernel.org>, Miguel Ojeda <ojeda-AT-kernel.org>, Boqun Feng <boqun-AT-kernel.org>, Gary Guo <gary-AT-garyguo.net>, Björn Roy Baron <bjorn3_gh-AT-protonmail.com>, Benno Lossin <lossin-AT-kernel.org>, Andreas Hindborg <a.hindborg-AT-kernel.org>, Alice Ryhl <aliceryhl-AT-google.com>, Trevor Gross <tmgross-AT-umich.edu>, Danilo Krummrich <dakr-AT-kernel.org>, David Airlie <airlied-AT-gmail.com>, Simona Vetter <simona-AT-ffwll.ch> |
| Subject: |
| [PATCH v3 0/5] gpu: drm: nova: enable calling into nova-core |
| Date: |
| Sat, 30 May 2026 00:27:40 +0900 |
| Message-ID: |
| <20260530-nova-exports-v3-0-1202aa339ef7@nvidia.com> |
| Cc: |
| John Hubbard <jhubbard-AT-nvidia.com>, Alistair Popple <apopple-AT-nvidia.com>, Timur Tabi <ttabi-AT-nvidia.com>, Zhi Wang <zhiw-AT-nvidia.com>, Eliot Courtney <ecourtney-AT-nvidia.com>, linux-kbuild-AT-vger.kernel.org, linux-kernel-AT-vger.kernel.org, rust-for-linux-AT-vger.kernel.org, nova-gpu-AT-lists.linux.dev, dri-devel-AT-lists.freedesktop.org, Alexandre Courbot <acourbot-AT-nvidia.com>, Joel Fernandes <joelagnelf-AT-nvidia.com> |
| Archive-link: |
| Article |
`nova-drm` is scheduled to expose a user-space API to receive IOCTLs
from user-mode drivers, and to call into `nova-core` to perform the
actual work. We are about to reach the state where we need the ability
to call into `nova-core`, but the current Rust build system does not
support this, and the solution will likely take at least a couple of
cycles to be merged.
In the meantime, this series introduces a Nova-local workaround for
`nova-drm` to call into `nova-core`. It generates the `nova-core`
metadata that `nova-drm` can use to resolve references at build-time,
and also builds a list of exported symbols for symbol resolution when
modules are loaded.
Since Rust symbols are long, this work ran into the limits on symbol
sizes `modpost` can handle. Thus, the first patch instructs the compiler
to inline initializers for some Rust basic types to avoid those long
symbol names when symbols from `nova-core` are exported. Interestingly,
this also results in a smaller nova-core binary size [1].
The rest of the patches enable inter-module calls from nova-drm to
nova-core.
This series is based on `drm-rust-next`.
[1] https://lore.kernel.org/all/DIN76NTFEU1N.1RT6G4IFD62RG@nv...
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
Changes in v3:
- Drop the modpost overflow detection patch as it is to be merged
through the KBuild tree.
- Drop obsolete (and actually unnecessary) changes to `pin_init`.
- Do not inline methods returning `impl PinInit` as they cannot
contribute to the long symbol names problem.
- Use `#[inline]` instead of `#[inline(always)]` for methods that could
create excessively long symbols.
- Link to v2: https://patch.msgid.link/20260527-nova-exports-v2-0-06de4...
Changes in v2:
- Rebase on top of HRT v5.
- Inline some `pin_init` and Rust basic types methods to avoid long
symbol names and optimize code.
- Print truncating modpost symbols and abort upon meeting them.
- Drop increase of `buf_printf`'s buffer.
- Drop obsolete nova-core renaming patch.
- Link to v1: https://patch.msgid.link/20260430-nova-exports-v1-0-7ca31...
---
Alexandre Courbot (5):
rust: inline some init methods
gpu: nova-core: export Rust symbols for dependent modules
gpu: nova-core: emit Rust metadata for dependent modules
gpu: drm: nova: build after nova-core metadata
[POC] drm: nova: demonstrate interaction with nova-core
drivers/gpu/drm/nova/Makefile | 15 ++++++++
drivers/gpu/drm/nova/driver.rs | 9 ++++-
drivers/gpu/nova-core/Makefile | 48 ++++++++++++++++++++++++-
drivers/gpu/nova-core/driver.rs | 59 +++++++++++++++++++++++--------
drivers/gpu/nova-core/gpu.rs | 9 +++--
drivers/gpu/nova-core/nova_core.rs | 4 +--
drivers/gpu/nova-core/nova_core_exports.c | 13 +++++++
rust/kernel/alloc/kbox.rs | 2 ++
rust/kernel/init.rs | 1 +
rust/kernel/sync/arc.rs | 2 ++
10 files changed, 141 insertions(+), 21 deletions(-)
---
base-commit: 0e42ec83d46ab8877d38d37493328ed7d1a24de8
change-id: 20260430-nova-exports-502f996c5aab
Best regards,
--
Alexandre Courbot <acourbot@nvidia.com>
