Re: [PATCH 3/7] rust: crc_ccitt: add CRC-CCITT abstraction

On 8/21/26 8:30 AM, Eric Biggers wrote:

> On Thu, Aug 20, 2026 at 02:55:45PM +0530, Ayush Singh wrote:
>> The module is gated behind the new RUST_CRC_CCITT_ABSTRACTIONS Kconfig
>> symbol, which selects CRC_CCITT, so the C library is only built when a
>> Rust user actually needs it.
>>
>> Signed-off-by: Ayush Singh <[email protected]>
>> ---
>>   MAINTAINERS                     |  1 +
>>   lib/crc/Kconfig                 |  7 +++++++
>>   rust/bindings/bindings_helper.h |  1 +
>>   rust/kernel/crc_ccitt.rs        | 26 ++++++++++++++++++++++++++
>>   rust/kernel/lib.rs              |  2 ++
>>   5 files changed, 37 insertions(+)
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 6008f16ae2ca..1e3b42eff741 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -6921,6 +6921,7 @@ T:	git https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git crc-ne
>>   F:	Documentation/staging/crc*
>>   F:	include/linux/crc*
>>   F:	lib/crc/
>> +F:	rust/kernel/crc*
>>   F:	scripts/gen-crc-consts.py
>>   
>>   CREATIVE SB0540
>> diff --git a/lib/crc/Kconfig b/lib/crc/Kconfig
>> index 927fc6a6b2b9..aceb8fe8f0ed 100644
>> --- a/lib/crc/Kconfig
>> +++ b/lib/crc/Kconfig
>> @@ -32,6 +32,13 @@ config CRC_CCITT
>>   	  The CRC-CCITT library functions.  Select this if your module uses any
>>   	  of the functions from <linux/crc-ccitt.h>.
>>   
>> +config RUST_CRC_CCITT_ABSTRACTIONS
>> +	bool "Rust CRC-CCITT abstractions"
>> +	depends on RUST
>> +	select CRC_CCITT
>> +	help
>> +	  This enables the Rust abstraction for the CRC-CCITT API.
> Like the other library kconfig symbols, this shouldn't have a prompt.
> It should just be selected by the other symbols that need it.

I was copying `RUST_SERIAL_DEV_BUS_ABSTRACTIONS`, which seems to have a 
prompt. Will remove in next revision.


>> diff --git a/rust/kernel/crc_ccitt.rs b/rust/kernel/crc_ccitt.rs
>> new file mode 100644
>> index 000000000000..6042ada16967
>> --- /dev/null
>> +++ b/rust/kernel/crc_ccitt.rs
> Is there a reason why the kconfig symbol is being put in lib/crc/ but
> the actual code is being put in rust/kernel/?  It seems inconsistent.
>
> - Eric


Was copying `RUST_SERIAL_DEV_BUS_ABSTRACTIONS`. It is also in 
`drivers/tty/serdev/Kconfig`.


The reason for introducing this symbol is that normally, crc_ccitt can 
be built as either builtin, a module, or just left out. However, for use 
from Rust abstractions, it can either be builtin, or left out. The 
module state is not supported. Is there a better way to deal with it?


Best Regards,

Ayush Singh