> On Tue, Mar 5, 2024, at 17:33, Avri Altman wrote: > >> On Tue, Feb 27, 2024 at 4:31 PM Jens Wiklander > <jens.wiklander@xxxxxxxxxx> wrote: > >> > >> I would mention in the commit that the subsystem is currently only > >> used with eMMC but is designed to be used also by UFS and NVME. > >> Nevertheless, no big deal so: > > Moreover, as the years went by, the differences between mmc and ufs > > grew: > > In mmc there are 7 rpmb operations, in ufs 9. > > In mmc the rpmb frame is 512Bytes, also in legacy ufs (up to including > > ufs3.1), but in ufs4.0 onward it can be 4k with extended header. > > See e.g. > > https://patchwork.kernel.org/project/linux-scsi/patch/20221107131038.2 > > 01724-3-beanhuo@xxxxxxxx/ In mmc the rpmb sequence is atomic, in ufs > > not. > > In ufs rpmb is a wlun in mmc a partition. > > Both protocols support in multi-region rpmb, but there are some > > differences there. > > How sure are we then that the user-visible ABI is sufficiently abstract to cover > all the hardware implementations? Are any of the changes you mention going to > be noticed by userspace or are they only visible to the kernel driver? Both in ufs & mmc rpmb today is accessed via user-space utils: In mmc via mmc-utils (ioctl) , and in ufs via ufs-utils using its bsg interface. No ABI changes are needed. Thanks, Avri > > Arnd
