[v2,0/8] DRM Rust abstractions

Message

Danilo Krummrich April 10, 2025, 11:55 p.m. UTC

This is the series for the initial DRM Rust abstractions, including DRM device /
driver, IOCTL, File and GEM object abstractions.

Compared to the original work from Lina, the patches in this series contain the
following modifications.

  - "rust: drm: ioctl: Add DRM ioctl abstraction"
      * wrap IOCTL data in Opaque<T> to avoid UB when creating a reference
      * original source archive: https://archive.is/LqHDQ

  - "rust: drm: add driver abstractions" (newly created)
      * Remove unnecessary DRM features
      * add #[expect(unused)] to avoid warnings
      * add sealed trait
      * original source archive: https://archive.is/Pl9ys

  - "rust: drm: add device abstraction" (newly created)
      * full rewrite of the drm::Device abstraction using the subclassing
        pattern
      * original source archive: http://archive.today/5NxBo

  - "rust: drm: add DRM driver registration" (newly created)
      * move VTABLE to drm::Device to prevent use-after-free bugs; VTABLE
        needs to be bound to the lifetime of drm::Device, not the
        drm::Registration
      * combine new() and register() to get rid of the registered boolean
      * remove file_operations
      * move struct drm_device creation to drm::Device
      * introduce Devres
      * original source archive: https://archive.is/Pl9ys

  - "rust: drm: file: Add File abstraction"
      * switch to the Opaque<T> type
      * fix (mutable) references to struct drm_file (which in this
        context is UB)
      * restructure and rename functions to align with common kernel
        schemes
      * write and fix safety and invariant comments
      * remove necessity for and convert 'as' casts
      * original source archive: https://archive.is/GH8oy

  - "rust: drm: gem: Add GEM object abstraction"
       * switch to the Opaque<T> type
       * fix (mutable) references to struct drm_gem_object (which in this
         context is UB)
       * drop all custom reference types in favor of AlwaysRefCounted
       * bunch of minor changes and simplifications (e.g. IntoGEMObject
         trait)
       * write and fix safety and invariant comments
       * remove necessity for and convert 'as' casts
       * original source archive: https://archive.is/dD5SL

A full diff between this series and the original work can be found in [1].

This patch series is also available in [2]; an example usage from nova-drm can
be found in [3].

[1] https://pastebin.com/qLBCfgTc
[2] https://gitlab.freedesktop.org/drm/misc/kernel/-/tree/topic/rust-drm
[3] https://gitlab.freedesktop.org/drm/nova/-/tree/staging/nova-drm

Changes in v2:
  - IOCTL: wrap data in Opaque<T> to avoid UB when creating a reference
  - driver: remove unnecessary FEATURE flags
  - driver: remove date field
  - MAINTAINERS: add files to both DRM and DRM MISC
  - change primary authorship of most patches

Asahi Lina (6):
  rust: drm: ioctl: Add DRM ioctl abstraction
  rust: drm: add driver abstractions
  rust: drm: add device abstraction
  rust: drm: add DRM driver registration
  rust: drm: file: Add File abstraction
  rust: drm: gem: Add GEM object abstraction

Danilo Krummrich (2):
  drm: drv: implement __drm_dev_alloc()
  MAINTAINERS: add DRM Rust source files to DRM DRIVERS

 MAINTAINERS                     |   2 +
 drivers/gpu/drm/drm_drv.c       |  58 ++++--
 include/drm/drm_drv.h           |   5 +
 rust/bindings/bindings_helper.h |   6 +
 rust/helpers/drm.c              |  19 ++
 rust/helpers/helpers.c          |   1 +
 rust/kernel/drm/device.rs       | 195 +++++++++++++++++++
 rust/kernel/drm/driver.rs       | 170 +++++++++++++++++
 rust/kernel/drm/file.rs         |  99 ++++++++++
 rust/kernel/drm/gem/mod.rs      | 321 ++++++++++++++++++++++++++++++++
 rust/kernel/drm/ioctl.rs        | 161 ++++++++++++++++
 rust/kernel/drm/mod.rs          |  19 ++
 rust/kernel/lib.rs              |   2 +
 rust/uapi/uapi_helper.h         |   1 +
 14 files changed, 1043 insertions(+), 16 deletions(-)
 create mode 100644 rust/helpers/drm.c
 create mode 100644 rust/kernel/drm/device.rs
 create mode 100644 rust/kernel/drm/driver.rs
 create mode 100644 rust/kernel/drm/file.rs
 create mode 100644 rust/kernel/drm/gem/mod.rs
 create mode 100644 rust/kernel/drm/ioctl.rs
 create mode 100644 rust/kernel/drm/mod.rs