"Jason A. Donenfeld" <Jason@xxxxxxxxx> writes: > The archrandom interface was originally designed for x86, which supplies > RDRAND/RDSEED for receiving random words into registers, resulting in > one function to generate an int and another to generate a long. However, > other architectures don't follow this. > > On arm64, the SMCCC TRNG interface can return between 1 and 3 words. On > s390, the CPACF TRNG interface can return between 1 and 32 words for the > same cost as for one word. On UML, the os_getrandom() interface can return > arbitrary amounts. > > So change the api signature to take a "words" parameter designating the > maximum number of words requested, and then return the number of words > generated. On powerpc a word is 32-bits and a doubleword is 64-bits (at least according to the ISA). I think that's also true on other 64-bit architectures. You could avoid any confusion by defining the API in terms of "longs" rather than "words". But that's just a comment, see what others think. > arch/powerpc/include/asm/archrandom.h | 30 ++------ > arch/powerpc/kvm/book3s_hv.c | 2 +- Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> (powerpc) cheers
