Hi Mauro, Hans,
While working on v1 for this patchset, I realized that we can go further by
converting the error-prone sections of our codec drivers to Rust. This also
does not need any bindings in order to work.
As yet another proof-of-concept, I have converted parts of the rkvdec driver.
Refer to instructions in v1 to test this.
Notice how:
1) many problematic memcpy's go away, these become a simple assignment in Rust.
2) it can interop seamlessly with the code in rkvdec-vp9.c that was already
converted in v1 of this series.
3) it can use the Rust version of `seg_feat_enabled` directly in vp9.rs, while
also using the C APIs from the v4l2-vp9-rs library in rkvdec-vp9.c
4) more modern things become available for the programmer, like iterators and
their methods without a performance penalty.
I want to propose the following:
Let's merge a non-RFC version of this series and gate it behind some kconfigs
so that we can switch between the C and Rust implementations. Users get the C
version by default, while we continuously test the Rust components on a CI for
a few months. This will hopefully be enough time until the next Media Summit.
My aim is to eventually deprecate the C parts once we're confident that the
Rust code is stable enough. I will keep my own tree, and send PRs to the media
tree if a rebase or fix is needed.
I believe this will not be disruptive nor require any extra work from anyone
but me.
-- Daniel
Again, applies on top of:
commit d9c1fae3e5b225f2e45e0bca519f9a2967cd1062
Author: Alice Ryhl <aliceryhl@xxxxxxxxxx>
Date: Fri Feb 9 11:18:22 2024 +0000
rust: file: add abstraction for `poll_table`
For those looking for a branch instead: https://gitlab.collabora.com/dwlsalmeida/for-upstream/-/tree/vp9-rs-rkvdec?ref_type=heads
Daniel Almeida (2):
v4l2-core: rewrite the VP9 library in Rust
media: rkvdec: rewrite parts of the driver in Rust
drivers/media/platform/verisilicon/Kconfig | 2 +-
.../platform/verisilicon/hantro_g2_vp9_dec.c | 38 +-
.../media/platform/verisilicon/hantro_hw.h | 8 +-
drivers/media/v4l2-core/Kconfig | 5 +
drivers/staging/media/rkvdec/Kconfig | 3 +-
drivers/staging/media/rkvdec/Makefile | 2 +-
drivers/staging/media/rkvdec/cbindgen.toml | 36 +
drivers/staging/media/rkvdec/common.rs | 19 +
drivers/staging/media/rkvdec/regs.rs | 237 ++
drivers/staging/media/rkvdec/rkvdec-vp9.c | 607 +----
drivers/staging/media/rkvdec/rkvdec_rs.h | 125 +
drivers/staging/media/rkvdec/rkvdec_rs.rs | 14 +
drivers/staging/media/rkvdec/vp9.rs | 636 +++++
include/media/v4l2-vp9-rs.h | 99 +
rust/bindings/bindings_helper.h | 1 +
rust/helpers.c | 7 +
rust/kernel/lib.rs | 2 +
rust/kernel/media.rs | 5 +
rust/kernel/media/v4l2_core.rs | 6 +
rust/kernel/media/v4l2_core/cbindgen.toml | 26 +
rust/kernel/media/v4l2_core/vp9.rs | 2053 +++++++++++++++++
21 files changed, 3415 insertions(+), 516 deletions(-)
create mode 100644 drivers/staging/media/rkvdec/cbindgen.toml
create mode 100644 drivers/staging/media/rkvdec/common.rs
create mode 100644 drivers/staging/media/rkvdec/regs.rs
create mode 100644 drivers/staging/media/rkvdec/rkvdec_rs.h
create mode 100644 drivers/staging/media/rkvdec/rkvdec_rs.rs
create mode 100644 drivers/staging/media/rkvdec/vp9.rs
create mode 100644 include/media/v4l2-vp9-rs.h
create mode 100644 rust/kernel/media.rs
create mode 100644 rust/kernel/media/v4l2_core.rs
create mode 100644 rust/kernel/media/v4l2_core/cbindgen.toml
create mode 100644 rust/kernel/media/v4l2_core/vp9.rs
--
2.43.0
