The mmc driver has some hooks to support rpmb access, but access is mainly facilitated from user space, e.g. mmc-utils.
The ufs driver has no concept of rpmb access - it is facilitated via user space, e.g. ufs-utils and similar. Both for ufs and mmc, rpmb access is defined in their applicable jedec specs. This is the case for few years now - AFAIK No new rpmb-related stuff is expected to be introduced in the near future. What problems, as far as mmc and ufs, are you trying to solve by this new subsystem? Thanks, Avri
