[PATCH] arm64/lib: add optimized implementation of sha_transform

[Marek Vasut]

On Tuesday, March 18, 2014 at 08:26:00 AM, Ard Biesheuvel wrote:
> On 17 March 2014 22:18, Marek Vasut <marex at denx.de> wrote:
> > On Friday, March 14, 2014 at 04:02:33 PM, Ard Biesheuvel wrote:
> >> This implementation keeps the 64 bytes of workspace in registers rather
> >> than on the stack, eliminating most of the loads and stores, and
> >> reducing the instruction count by about 25%.
> >> 
> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
> >> ---
> >> Hello all,
> >> 
> >> No performance numbers I am allowed to share, unfortunately, so if
> >> anyone else (with access to actual, representative hardware) would care
> >> to have a go, I would be very grateful.
> >> 
> >> This can be done by building the tcrypt.ko module
> >> (CONFIG_CRYPTO_TEST=m), and inserting the module using 'mode=303' as a
> >> parameter (note that the insmod always fails, but produces its test
> >> output to the kernel log). Also note that the sha_transform() function
> >> will be part of the kernel proper, so just rebuilding the sha1_generic
> >> module is not sufficient.
> >> 
> >> Cheers,
> > 
> > Won't the function sha_transform() collide with the one in lib/sha1.c ?
> > Or will the one in lib/sha1.c be overriden somehow ?
> 
> No, this works pretty well, in fact: arch/*/lib has precedence over
> lib/, and objects (declared with lib-y +=)  are only included to
> satisfy unresolved dependencies. So the second (generic) sha1.o will
> not get linked.

Thanks for clearing this !

> > Otherwise:
> > 
> > Reviewed-by: Marek Vasut <marex at denx.de>
> 
> Thanks. I did send a v2 which is actually a lot different from the
> version you reviewed, so I won't carry over your reviewed-by without
> your acknowledgement.

Thanks!

Best regards,
Marek Vasut