Re: [PATCH v5 2/3] mmc: block: register RPMB partition with the RPMB subsystem

[Jens Wiklander]

On Mon, Apr 29, 2024 at 9:36 PM Avri Altman <Avri.Altman@xxxxxxx> wrote:
>
> > > > >
> > > > > Is it possible that idata->buf is not DMA capable? Any other ideas?
> > > >
> > > > Thanks for testing. I don't know, the idata->buf is allocated using
> > > > alloc_pages_exact(nr_pages * PAGE_SIZE, GFP_KERNEL | __GFP_ZERO); in
> > > > optee_pool_op_alloc_helper().
> > >
> > > Is this really true for idata->buf or isnt the complete RPMB frame
> > > memory allocated like this and therefore idata->buf not page aligned?
> >
> > You're right.
> Maybe add an assert of PAGE_ALIGNED(idata->buf)?

That might be a bit much. It turned out that there was a 2-byte
alignment causing the trouble. I don't know exactly what's needed, but
the amount used by kmalloc() by default is good.

Cheers,
Jens

>
> Thanks,
> Avri
>
> >
> > >
> > > For RPMB via tee-supplicant the idata->buf is allocated within
> > > memdup_user and therefore page aligned.
> >
> > Yes, that's a difference. Have you tested with page-aligned buffers to see if it
> > helps?