[PATCH v2 0/7] gpu: drm: nova: enable calling into nova-core

[Alexandre Courbot <acourbot@nvidia.com>]

`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
currently 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; however the overflow path was not properly
handled, which resulted in late failures. The first patch makes
`modpost` fail on symbols that are too long for its internal buffer and
report them. It is not strictly necessary for this series and can be
merged independently if preferred.

The second and third patches instruct the compiler to inline some
methods of `pin_init` and Rust basic types to avoid those long symbol
names. 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` with [2] and [3] applied.

[1] https://lore.kernel.org/all/DIN76NTFEU1N.1RT6G4IFD62RG@nvidia.com/
[2] https://lore.kernel.org/all/20260525202921.124698-1-dakr@kernel.org/
[3] https://lore.kernel.org/all/20260525225838.276108-1-dakr@kernel.org/

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
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-v1-0-7ca31664e983@nvidia.com

---
Alexandre Courbot (7):
      scripts: modpost: detect and report truncated buf_printf() output
      pin_init: always inline the #ident and #project_ident methods
      rust: always 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            | 46 +++++++++++++++++++++++-
 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 ++
 rust/kernel/types.rs                      |  3 ++
 rust/pin-init/internal/src/pin_data.rs    |  2 ++
 scripts/mod/modpost.c                     | 11 +++++-
 13 files changed, 154 insertions(+), 22 deletions(-)
---
base-commit: 79c29e27d676a74f9238506a5fe2134637356708
change-id: 20260430-nova-exports-502f996c5aab

Best regards,
--  
Alexandre Courbot <acourbot@nvidia.com>