On Sat, 31 Jul 2021 at 22:49, Andre Przywara <andre.przywara@xxxxxxx> wrote: > > The "Arm True Random Number Generator Firmware Interface"[1] provides > an SMCCC based interface to a true hardware random number generator. > So far we are using that in arch_get_random_seed(), but it might be > useful to expose the entropy through the /dev/hwrng device as well. This > allows to assess the quality of the implementation, by using "rngtest" > from the rng-tools package, for example. > > Patch 1 creates a platform device, triggered by the previous discovery > of the SMCCC TRNG service. > Patch 2 implements a hw_random platform driver, which is instantiated > through this said platform device. > > The driver can be loaded as module, or built into the kernel. > > [1] https://developer.arm.com/documentation/den0098/latest/ > > Changelog v3 ... v4: > - drop pointless driver loading message > - drop unneeded init() routine > > Changelog v2 ... v3: > - split platform device and driver > > Changelog v1 ... v2: > - fix building as a module > - de-register device upon exit > - mention module name in Kconfig > > Andre Przywara (2): > firmware: smccc: Register smccc_trng platform device > hwrng: Add Arm SMCCC TRNG based driver > Reviewed-by: Ard Biesheuvel <ardb@xxxxxxxxxx> > drivers/char/hw_random/Kconfig | 14 +++ > drivers/char/hw_random/Makefile | 1 + > drivers/char/hw_random/arm_smccc_trng.c | 123 ++++++++++++++++++++++++ > drivers/firmware/smccc/smccc.c | 17 ++++ > 4 files changed, 155 insertions(+) > create mode 100644 drivers/char/hw_random/arm_smccc_trng.c > > -- > 2.17.6 >
