Well, __x86_64__ should be a build-in define of the compiler while
CONFIG_X86_64 is defined for 64 bit builds in include/generated/autoconf.h.
So by using the latter we should be on the safe side but if your compiler
defines __x86_64__ for 32-bit builds it's simply broken. Also git grep
showed quite a few more places using __x86_64__ so those would miscompile on
your toolchain, too.
But it looks like linux-next is just missing
559ad0ff1368baea14dbc3207d55b02bd69bda4b from Herbert's git repo at
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git.
That should fix the build issue.
Kind Regards,
Mathias
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