With ARCH=arm64, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/char/hw_random/cavium-rng.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/char/hw_random/cavium-rng-vf.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/char/hw_random/arm_smccc_trng.o
Add the missing invocations of the MODULE_DESCRIPTION() macro.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Don't set drvdata, there's nobody who reads it.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The SMCCC_RET_TRNG_NO_ENTROPY switch arm is never used because the
NO_ENTROPY return value is negative and negative values are handled
above the switch by immediately returning.
Fix by handling errors using a default arm in the switch.
Fixes: 0888d04b47 ("hwrng: Add Arm SMCCC TRNG based driver")
Signed-off-by: James Cowgill <james.cowgill@blaize.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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.
Add a simple platform driver implementing the hw_random interface.
The corresponding platform device is created by the SMCCC core code,
we just match it here by name and provide a module alias.
Since the firmware takes care about serialisation, this can happily
coexist with the arch_get_random_seed() bits.
[1] https://developer.arm.com/documentation/den0098/latest/
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
