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

Alexandre Courbot posted 7 patches 1 month, 2 weeks ago
There is a newer version of this series
drivers/gpu/drm/nova/Makefile             | 15 ++++++++++
drivers/gpu/drm/nova/driver.rs            |  6 ++++
drivers/gpu/nova-core/Kconfig             |  2 +-
drivers/gpu/nova-core/Makefile            | 48 ++++++++++++++++++++++++++++++-
drivers/gpu/nova-core/driver.rs           | 20 +++++++++++--
drivers/gpu/nova-core/gpu.rs              |  9 ++++--
drivers/gpu/nova-core/nova_core.rs        |  4 +--
drivers/gpu/nova-core/nova_core_exports.c | 11 +++++++
scripts/mod/modpost.c                     | 13 +++++++--
9 files changed, 117 insertions(+), 11 deletions(-)
[PATCH 0/7] gpu: drm: nova: enable calling into nova-core
Posted by Alexandre Courbot 1 month, 2 weeks ago
`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 would like to introduce 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 of `modpost`,
which the first two patches try to address: the first one, by detecting
and reporting buffer overflow situations that were ignored until now;
the second, by increasing the size of the buffer used to build the
symbol names, so `nova-core`'s symbols can fit.

@Miguel: I expect the design used here will allow us to smoothly switch
to the new build system once it is merged; I hope you are ok with this
temporary workaround.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
Alexandre Courbot (7):
      scripts: modpost: detect and report truncated buf_printf() output
      scripts: modpost: increase buf_printf's buffer size
      gpu: nova-core: rename module from nova_core to nova-core
      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            |  6 ++++
 drivers/gpu/nova-core/Kconfig             |  2 +-
 drivers/gpu/nova-core/Makefile            | 48 ++++++++++++++++++++++++++++++-
 drivers/gpu/nova-core/driver.rs           | 20 +++++++++++--
 drivers/gpu/nova-core/gpu.rs              |  9 ++++--
 drivers/gpu/nova-core/nova_core.rs        |  4 +--
 drivers/gpu/nova-core/nova_core_exports.c | 11 +++++++
 scripts/mod/modpost.c                     | 13 +++++++--
 9 files changed, 117 insertions(+), 11 deletions(-)
---
base-commit: 11a63a5335eb7b5da4ca38014fa83be5d437144d
change-id: 20260430-nova-exports-502f996c5aab

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