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SubjectRe: [PATCH] crypto: serpent - add x86_64/avx assembler implementation
Quoting Johannes Goetzfried  
<Johannes.Goetzfried@informatik.stud.uni-erlangen.de>:

> Hello,
>
>> Should be serpent_sse2_glue.c?
>
> Yeah, same error as in the other patch :-)
>
>> >+}, {
>> >+ .cra_name = "ecb(serpent)",
>> >+ .cra_driver_name = "ecb-serpent-avx",
>> >+ .cra_priority = 400,
>>
>> serpent_sse2_glue.c has priority 400 too, so you should increase
>> priority here to 500.
>
> You are right. Actually it is useless to load both modules at the
> same time and
> so this shouldn't be a problem. But better be safe. I'll resend this patch as
> well.
>

Thing is that since both have MODULE_ALIAS(serpent), they both get
loaded with 'modprobe serpent' etc.

>> Actually about duplicating glue code.. is it really needed? On
>> x86_64, both avx and sse2 versions process 8-blocks parallel and
>> therefore glue code could be easily shared (as is done in SHA1
>> SSSE3/AVX).
>
> I thought about doing it the way as it is done in the SHA1-Module.
> But I don't
> think that's a good idea, because then I had to compile both
> implementations in
> the same module and decide at runtime which one to use depending on the
> processor capabilities. This would result in an increasing object
> size and on a
> specific processor only one implementation is used. I think it's better to
> decide statically at compile-time which implementation to use.
> I agree, the code duplication is ugly, and have a different approach. All the
> glue code shared by both implementations can be moved to a
> serpent_common_glue.c
> file and only the module init stuff needs to be seperate. This should reduce
> the code size and keeps the possibility of compiling only one
> implementation. I
> will send a second patch which should do the job.
>

Looks better.

Maybe later when I have time, I'll check if all glue code for 16-byte
block-ciphers found in arch/x86/crypto could be merged in to single
helper module.

-Jussi



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