• Harald Freudenberger's avatar
    s390/crypto: Provide s390 specific arch random functionality. · 4c637cd8
    Harald Freudenberger authored
    
    
    This patch introduces s390 specific arch random functionality.
    There exists a generic kernel API for arch specific random
    number implementation (see include/linux/random.h). Here
    comes the header file and a very small static code part
    implementing the arch_random_* API based on the TRNG
    subfunction coming with the reworked PRNG instruction.
    
    The arch random implementation hooks into the kernel
    initialization and checks for availability of the TRNG
    function. In accordance to the arch random API all functions
    return false if the TRNG is not available. Otherwise the new
    high quality entropy source provides fresh random on each
    invocation.
    
    The s390 arch random feature build is controlled via
    CONFIG_ARCH_RANDOM. This config option located in
    arch/s390/Kconfig is enabled by default and appears
    as entry "s390 architectural random number generation API"
    in the submenu "Processor type and features" for s390 builds.
    
    Signed-off-by: default avatarHarald Freudenberger <freude@linux.vnet.ibm.com>
    Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
    4c637cd8