"Jason A. Donenfeld" [off-list ref] writes:

When RDRAND was introduced, there was much discussion on whether it
should be trusted and how the kernel should handle that. Initially, two
mechanisms cropped up, CONFIG_ARCH_RANDOM, a compile time switch, and
"nordrand", a boot-time switch.

...

 arch/arm/include/asm/archrandom.h             |  2 ++
 arch/arm64/Kconfig                            |  8 ------
 arch/arm64/include/asm/archrandom.h           | 10 --------
 arch/arm64/kernel/cpufeature.c                |  2 --
 arch/powerpc/Kconfig                          |  3 ---
 arch/powerpc/include/asm/archrandom.h         |  3 ---
 arch/powerpc/include/asm/machdep.h            |  2 --
 arch/powerpc/platforms/microwatt/Kconfig      |  1 -
 arch/powerpc/platforms/powernv/Kconfig        |  1 -
 arch/powerpc/platforms/pseries/Kconfig        |  1 -

Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

cheers