This patch series introduces the dma::Coherent API Gary worked out in the
context of his I/O projection work.

Additionally, introduce dma::CoherentBox, a type that encapsulates a
dma::Coherent object before its DMA address is exposed to the device.
dma::CoherentBox can guarantee exclusive access to the inner dma::Coherent
object and implement Deref and DerefMut.

Also add Coherent::init() and Coherent::init_with_attrs() so we can directly
initialize a new dma::Coherent object through an impl Init<T, E>.

Changes in v2:
  - Rebase onto the DMA and nova-core fixes that went into -rc4.
  - Rename CoherentInit to CoherentBox.
  - Add a bunch of #[inline] attributes.
  - Remove a few unnecessary trait bounds in "rust: dma: add generalized
    container for types other than slices".
  - Fix a typo and convert core::ptr::from_mut(&mut self[i]) into
    &raw mut self[i].

Danilo Krummrich (5):
  rust: dma: use "kernel vertical" style for imports
  rust: dma: introduce dma::CoherentBox for memory initialization
  rust: dma: add Coherent:init() and Coherent::init_with_attrs()
  gpu: nova-core: use Coherent::init to initialize GspFwWprMeta
  gpu: nova-core: convert Gsp::new() to use CoherentBox

Gary Guo (3):
  rust: dma: add generalized container for types other than slices
  rust: dma: add zeroed constructor to `Coherent`
  gpu: nova-core: convert to new dma::Coherent API

 drivers/gpu/nova-core/dma.rs      |  19 +-
 drivers/gpu/nova-core/falcon.rs   |   5 +-
 drivers/gpu/nova-core/gsp.rs      |  68 ++--
 drivers/gpu/nova-core/gsp/boot.rs |   7 +-
 drivers/gpu/nova-core/gsp/cmdq.rs |  21 +-
 drivers/gpu/nova-core/gsp/fw.rs   | 128 +++---
 rust/kernel/device.rs             |   4 +-
 rust/kernel/dma.rs                | 632 +++++++++++++++++++++++-------
 samples/rust/rust_dma.rs          |   8 +-
 9 files changed, 626 insertions(+), 266 deletions(-)


base-commit: a19457958c3018783881c4416f272cd594f13049
-- 
2.53.0

On Sat Mar 21, 2026 at 4:45 AM JST, Danilo Krummrich wrote:
> This patch series introduces the dma::Coherent API Gary worked out in the
> context of his I/O projection work.
>
> Additionally, introduce dma::CoherentBox, a type that encapsulates a
> dma::Coherent object before its DMA address is exposed to the device.
> dma::CoherentBox can guarantee exclusive access to the inner dma::Coherent
> object and implement Deref and DerefMut.
>
> Also add Coherent::init() and Coherent::init_with_attrs() so we can directly
> initialize a new dma::Coherent object through an impl Init<T, E>.

The series,

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>

Based on this I have been able to remove nova-core's `DmaObject` and
consequently its now-useless `dma` module. It's indeed much nicer. I'll
submit the series after some more cleanup and testing.

On Fri Mar 20, 2026 at 8:45 PM CET, Danilo Krummrich wrote:

Applied to drm-rust-next, thanks!

> Danilo Krummrich (5):
>   rust: dma: use "kernel vertical" style for imports
>   rust: dma: introduce dma::CoherentBox for memory initialization

    [ Remove unnecessary trait bounds. - Danilo ]

>   rust: dma: add Coherent:init() and Coherent::init_with_attrs()
>   gpu: nova-core: use Coherent::init to initialize GspFwWprMeta
>   gpu: nova-core: convert Gsp::new() to use CoherentBox

    rust: dma: remove dma::CoherentAllocation<T>

> Gary Guo (3):
>   rust: dma: add generalized container for types other than slices
>   rust: dma: add zeroed constructor to `Coherent`

    [ Use kernel import style. - Danilo ]

>   gpu: nova-core: convert to new dma::Coherent API