[PATCH 0/3] Character device abstractions for Rust

[Josef Zoller]

Writing character devices is a common way to start writing kernel code,
especially because of the book "Linux Device Drivers", which is still
one of the best resources to learn about Linux kernel programming. To
allow an easier entry into Rust kernel programming specifically, this
series adds abstractions for these kinds of devices to the Rust API.

I also included a sample that demonstrates how to use these abstractions
to create the simplest example from LDD3, the "scull" device.

I'm also aware of the patch series about misc devices that was sent
recently. I think these are both valuable additions to the Rust API, and
could even be combined in some way, in which case the file operations
abstractions in both series should probably be separated and
generalized. But I'm still sending this series as it is, because it is
my first ever patch and I could use some feedback on my approach.

This series depends on the File abstraction patch [1] and the
Opaque::try_ffi_init patch [2], however, the latter is such a small
change that it could easily be included in this series if necessary.

Link: https://lore.kernel.org/all/20240915-alice-file-v10-3-88484f7a3dcf@xxxxxxxxxx/ [1]
Link: https://lore.kernel.org/all/20241001-b4-miscdevice-v2-1-330d760041fa@xxxxxxxxxx/ [2]
Signed-off-by: Josef Zoller <josef@xxxxxxxxxxxxxxxxxxxxx>
---
Josef Zoller (3):
      rust: char_dev: add character device abstraction
      rust: macros: add IoctlCommand derive macro
      samples: rust: add character device sample

 rust/bindings/bindings_helper.h |   1 +
 rust/helpers/fs.c               |  16 +
 rust/kernel/char_dev.rs         | 976 ++++++++++++++++++++++++++++++++++++++++
 rust/kernel/init/macros.rs      |  10 +-
 rust/kernel/ioctl.rs            | 236 +++++++++-
 rust/kernel/lib.rs              |   1 +
 rust/kernel/prelude.rs          |   2 +-
 rust/macros/ioctl_cmd.rs        | 202 +++++++++
 rust/macros/lib.rs              |  21 +
 samples/rust/Kconfig            |  10 +
 samples/rust/Makefile           |   1 +
 samples/rust/rust_char_dev.rs   | 506 +++++++++++++++++++++
 12 files changed, 1977 insertions(+), 5 deletions(-)
---
base-commit: ce1c54fdff7c4556b08f5b875a331d8952e8b6b7
change-id: 20241011-rust-char-dev-f82eb3e29899
prerequisite-patch-id: be636dd988fbd1f993df5fe7cd10eabfadd319b2
prerequisite-patch-id: 478b4285f3752e64043d2e3b5ccd786ef039f659

Best regards,
-- 
Josef Zoller <josef@xxxxxxxxxxxxxxxxxxxxx>