Re: [PATCH 05/29] crypto: talitos - Prepare crypto implementation file splitting

[Paul Louvel]

Hi Christophe,

> Le 28/05/2026 à 11:08, Paul Louvel a écrit :
>> Remove the static qualifier on multiple function that will be called
>> inside each crypto implementation file.
>> Add them to the main driver header file.
>
> I didn't have time to look at the generated text yet but I'm a bit 
> sceptic with this change, or more than the change itself, about its 
> purpose. And even more when I see patches 24 and 25.

About patch 24 and 25: one of the main purpose of this series is to get rid of
the is_sec1 scattered around the core code of the driver.

> Most functions here are small helpers. To be shared between several C 
> files they deserve becoming static inlines in talitos.h, not global 
> functions.

I did not look at the generated text either for this change but I bet the
compiler is inlining these calls. Adding them as static inline is more explicit.

I understand that there is a performance penalty, since there will be no
inlining, and a memory dereferencing for a call through function pointer.

> Indeed, most of the time is_sec1 is known at build time because in most 
> cases has_ftr_sec1() will constant fold into true or false during build. 
> This is because it is very unlikely that someone build a kernel to run 
> on both MPC 82xx and MPC 83xx at the same time. Therefore it is really 
> unlikely that this in built with both CRYPTO_DEV_TALITOS1 and 
> CRYPTO_DEV_TALITOS2 at the same time.

As for patch 24, 25 and onwards, the same space optimization apply here. If the
kernel is built with CRYPTO_DEV_TALITOS1, there will be no SEC2-related function
in the generated text, and vice versa.

>
> I can understand for a function like talitos_submit() but not for 
> functions like to_talitos_ptr() or to_talitos_ptr_ext_set() whose 
> purpose is really to get inlined into the caller.
>
> Christophe
>

These changes are needed to split the driver into multiple files.

Best regards,
Paul.

-- 
Paul Louvel, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com