[PATCH v3 0/6] Add FIELD_MODIFY() helper

[Jie Luo]

On 4/19/2025 1:04 AM, Yury Norov wrote:
>>>> I think a bunch of people have found them, tooling notwithstanding.
>>>>
>>>> As for the documentation, the commit message in 00b0c9b82663ac would
>>>> be advantageously promoted to full-fledged kernel-doc.
>>> The FIELD_MODIFY() and uxx_replace_bits() are simply different things.
>>>
>>> FIELD_MODIFY() employs __BF_FIELD_CHECK(), which allows strict
>>> parameters checking at compile time. And people like it. See
>>> recent fixed-size GENMASK() series:
>>>
>>> https://patchwork.kernel.org/comment/26283604/
>> I don't care much for what people like or not. I don't see this
>> FIELD_MODIFY() as a particular improvement on *_replace_bits().
> Sad to hear that. Those people are all kernel engineers, and they
> deserve some respect.
> 
> We are talking about tooling here. People use tools only if they like
> them. Luo likes FIELD_MODIFY() over (yes, undocumented and ungreppable)
> xx_replace_bits() for the reasons he described very clearly. He's going
> to use it in his driver shortly, and this arm64 detour has been made
> after my request.
> 
>  From my perspective, both functions have their right to live in kernel.
> They are similar but not identical.
> 
> I'll take patch #1 in my branch. Regarding ARM64 part - it's up to you
> either to switch to FIELD_MODIFY(), _replace_bits(), or do nothing.
> 
> Thanks,
> Yury

Thank you for reviewing and discussing this patch series. The newly
added macro FIELD_MODIFY() will be utilized by the Qualcomm PPE (Packet
Processing Engine) Ethernet driver. Regarding the ARM64 core files,
could you please provide guidance on the preferred approach?